Electronics Projects

Buck/Boost Charge Pump Regulator Powers White LEDs from a Wide 1.6 Volt to 5.5 Volt Input: Maxim Application Note #1021 (app note added 7/03)

Buck/Boost Reference Design: This reference design presents an alternative to the typical boost power regulator. A buck converter IC is used to generate a higher voltage needed by the white light LED power from a Ni-Cd battery. This circuit operates by turning the high switch on, connecting the battery voltage across the inductor. Once sufficient energy is stored in the inductor, the high side switch is turned off. The inductor current drives the switching node negative and energy is delivered through the low side into the output capacitor. This is essentially a lossless switching event. Also, since the high side and low side switches are MOSFET's, voltage drop can be very low as compared to a diode implementation so efficiency can be high. Regulation is achieved by monitoring the current through the LED with a current sense resistor and comparing it to an internal 0.45 volt reference within the converter IC. Current and thereby, illumination is varied by modifying the current sense resistor voltage. (added 3/05)

Buck/Boost Regulator Suits Battery Operation: 09/04/03 EDN Design Ideas / (added 1/05) A buck/boost converter can step a voltage up or down. Such a converter is appropriate for battery-powered applications. One application derives a regulated 14.1V at 1A from 12V solar panels with 9 to 18V variation. In this type of battery application, efficiency is an important factor; hence, this design uses an inexpensive synchronous-rectifier-based MC33166/7 circuit....

Buck/Boost-Based LED Drivers using the HV9910: Supertex Semiconductors (app note added 7/06)

Constant on Time Buck/Boost Regulator Converts a Positive Input to a Negative Output: 12/07/04 EDN Design Ideas / (added 11/05) Buck regulators find wide application as step-down regulators for converting large positive input voltages into a smaller positive output voltages. Figure 1 shows a simplified buck regulator that operates in continuous-conduction mode—that is, the inductor current always remains positive. The output voltage, VOUT, is equal to D×VIN, where D is the duty-cycle ratio of the buck switc...

Get Buck/Boost Performance from a Boost regulator: 07/11/02 EDN Design Ideas / (added 1/05) The SEPIC (single-ended, primary-inductance-converter) topology is generally a good choice for voltage regulators that must produce an on output voltage that falls in the middle of the input-voltage range, such as a 5V output from a 2.7 to 6V input, The topology has some disadvantages, however. The efficiency of a SEPIC circuit fares worse than that of buck and boost regulators, and SEPIC desig......

Industry’s First 4-Switch Buck/Boost Controller Achieves Highest Efficiency using a Single Inductor: DN369 - Design Notes (Linear Technology) (app note added 1/06)

LDO Buck/Boost 2 Sync Buck Sync Boost Reference Design: LDO, Buck/Boost, 2 Sync. Buck, Sync. Boost with Vin 2.7-4.2 V LiION or 4.5-6.5 V adapter. Multiple output voltages of 1.5 V, 2.5 V, 3.3 V and 8 V. The total output power is 5.5 W. (added 3/05)

LTC1626: Step-Down Converter Operates from Single Li-ION Cell: DN196 - Design Notes (Linear Technology) (app note added 1/06)

Maximizing Start up Loads with the LM3352 Regulated Buck/Boost Switched Capacitor Converter: National Semiconductor Application Note 27 Mar2000 (app note added 7/02)

Micropower Buck/Boost Circuits Part 1: Converting Three Cells to 3.3V*: DN109 - Design Notes (Linear Technology) (app note added 1/06)

Micropower Buck/Boost Circuits Part 2: Converting Four Cells to 5V*: DN110 - Design Notes (Linear Technology) (app note added 2/06)

No Design Switiching Regulator 5V Buck/Boost (Positive to Negative) Regulator: DN49 - Design Notes (Linear Technology) (app note added 1/06)

Positive to Negative Buck/Boost Converter using LM267X SIMPLE SWITCHER® Regulators: National Semiconductor Application Note 27 Mar2000 (app note added 7/02)

Single Inductor Tiny Buck/Boost Converter Provides 95% Efficiency in Lithium-Ion to 3.3V Applications: DN275 - Design Notes (Linear Technology) (app note added 1/06)

Step Up/Step Down Current Source Charges Batteries: 06/06/96 EDN Design Ideas / (added 11/05) For battery charging, the highly efficient step-down (buck) configuration is usually the topology of choice. However, a different approach is necessary if the following conditions prevail: The supply voltage is less than the battery voltage, or, even worse, the supply voltage ranges above and below the battery voltage.

Step-Down Converter Operates from Single Li-ION Cell: DN196 - Design Notes (Linear Technology) (app note added 1/06)

Synchronous Buck Reference Design #2: This reference design is synchronous Buck/Boost converter that can deliver up to 3.8 A of continuous current at -5 V from a 5 V input. This topology uses a synchronous buck controller (TPS5103) referenced to the negative output rail. The synchronous MOSFETs allow this design to achieve a peak efficiency of 88%. In addition, the TPS5103 provides a soft-start function and over-current protection. (added 3/05)

Synchronous Buck/Boost High Power White LED Driver: Linear Technology LT3453 (app note added 2/05)

Up/Down Sequence of Supplies Using the ADM1060: AN-667 - Analog Devices Application Note (app note added 6/06)

3.3V converter delivers 3W from Li-ION battery : 11/05/98 EDN-Design Ideas / (added 11/05) Lithium-ion batteries are rapidly gaining popularity in portable applications because of their superior energy density, low self-discharge rate, and high cell voltage. When you use one Li-ion battery to power a 3.3V dc/dc converter; however, you encounter a problem, because the battery voltage can be higher or lower than 3.3V. When fully charged, a Li-ion cell has approximately 4.2V output; when fully discharged, the voltage is approximately 2.5V. Therefore, you cannot use a simple buck or boost topology with a single inductor to generate a regulated 3.3V output. Some designs boost the voltage to approximately 4.3V and then use a low-dropout regulator to produce the 3.3V. This approach is inefficient, and efficiency is a crucial consideration in battery-powered applications. The circuit in Figure 1 offers a solution to the problem....

4MHz Monolithic Synchronous Step-Down Regulators Bring High Efficiency to Space-Sensitive Applications: DN304 - Design Notes (Linear Technology) (app note added 6/06)

60V High Efficiency Buck Switching Regulators in SO-8: DN202 - Design Notes (Linear Technology) (app note added 1/06)

60V/3A Step-Down DC/DC Converter Maintains High Efficiency over a Wide Input Range: DN301 - Design Notes (Linear Technology) (app note added 1/06)

Add an auxiliary Voltage to a Buck regulator: 10/31/02 EDN Design Ideas / (added 1/05) You often need more than one regulated output voltage in a system. A frequently used and reasonably simple way to create this auxiliary output voltage is to add a second winding to the output inductor, creating a coupled inductor or a transformer, followed by a diode to rectify (peak-detect) this output voltage....

AN-1146: Designing a Multi-Phase Asynchronous Buck Regulator using the LM2639: National Semiconductor Application Note 27 Mar2000 (app note added 7/02)

AN-1197: Selecting Inductors for Buck Converters: National Semiconductor - Application Note (app note added 7/06)

AN-1253: Wide-Input, High Voltage Buck Converter: National Semiconductor - Application Note (app note added 2/06)

AN-1319: Analysis and Design of a Hysteretic Constant Frequency Buck Regulator using the LM5007: National Semiconductor - Application Note (app note added 7/06)

AN-6003 / 'Shoot-through' in Synchronous Buck Converters: Fairchild Application Notes / (app note added 6/06)

AN-6005 / Synchronous buck MOSFET loss calculations with Excel model: Fairchild Application Notes / (app note added 6/06)

AN793: Power Management in Portable Applications: Understanding the Buck Switchmode Power Converter: Microchip Application Note - Published 18-Jul-01 (app note added 2/06)

AN874: Buck Configuration High-Power LED Driver: Microchip Application Note - Published 4-Jan-06 (app note added 6/06)

AN968: Simple Sychronous Buck Regulator: MCP1612: Microchip Application Note - Published 14-Jan-05 (app note added 2/06)

Analysis and Design of a Hysteretic Constant Frequency Buck Regulator using the LM5007: National Semiconductor - Application Note (app note added 7/06)

AN-H48: Buck-Based LED Drivers using the HV9910: Supertex Semiconductors (app note added 6/06)

Boost Controller Drives Buck Converter: 02/03/97 EDN Design Ideas / (added 3/05) -- By adding an external Switching Transistor, you can use a step up dc/dc Converter to step down voltages to produce an efficient Battery Powered Power Supply, this example Circuit can step down inputs as Low as2V to Outputs as Low as1.25V, with efficiency as high as 80%

Buck Boost Regulator Suits Battery Operation: 09/04/03 EDN Design Ideas / (added 1/05) A buck/boost converter can step a voltage up or down. Such a converter is appropriate for battery-powered applications. One application derives a regulated 14.1V at 1A from 12V solar panels with 9 to 18V variation. In this type of battery application, efficiency is an important factor; hence, this design uses an inexpensive synchronous-rectifier-based MC33166/7 circuit....

Buck Configuration High-Power LED Driver: Microchip Application Note - Published 4-Jan-06 (app note added 6/06)

Buck Converter Chargers also Provides System Power: 05/22/97 EDN Design Ideas / (added 4/02) -- Switching Regulator provides the charge voltage setpoint with Current regulation, and second Switching Regulator provides5V System Power -- Many systems require long-time operation during periods of power loss. Often, a gel or wet-cell lead-acid battery is the best choice because of high capacity and relatively low cost. The battery charges during normal operation and powers the system during power loss. These systems require a circuit to charge the battery as well as to regulate the system's VCC. The design must provide a current-limited voltage to the battery for charging and still develop system VCC in the charge or the discharge condition.....

Buck Converter Handles Battery Backup System: 04/24/03 EDN Design Ideas / (added 12/04) A synchronous buck converter is inherently bidirectional. That is, it transfers energy from input to output as a buck regulator when the output voltage is low, but, when the output voltage is high, the converter acts as a boost regulator, transferring power from output to input. This Design Idea shows how to use this bidirectional energy transfer to automatically recharge a battery when the mai......

Buck converter works efficiently from phone line: 02/15/00 EDN-Design Ideas / (added 2/06)

Buck IC Boosts Battery Voltage for White LED: 04/24/03 EDN Design Ideas / (added 1/05) White-light LEDs are finding their way into many markets that incandescent bulbs once served. Flashlights are among the newer applications in which reliability, ruggedness, and ability to control the power draw of the LEDs make these devices attractive. With incandescent bulbs, the power management for the device is a simple on-off switch....

Buck or Boost: Rugged Fast 60V Synchronous Controller Does Both: DN370 - Design Notes (Linear Technology) (app note added 1/06)

Buck Reference Design: This reference design is a buck converter that can deliver up to 2A of continuous current at -24 V from an input range of -35 V to -75 V. By referencing the UCC3813 controller to the negative input rail, the N-channel MOSFET is easily driven. This design achieves a peak efficiency greater than 95%. The UCC3813 provides current mode control for excellent line and load transient response. (added 3/05)

Double Data Rate Power Supply using the Tl5002 Voltage Tracking Regulator: The TL5002EVM-180 synchronous buck converter provides a 12A reference design for evaluating the performance of the TL5002 PWM control IC and the TPS2837 MOSFET driver for Double Data Rate (DDR) memory applications. (added 3/05)

Dual High-Current Power Supply Kit: The National Semiconductor Power Supply Kit is designed around the National LM2636, a synchronous buck regulator. It provides over 28 amps of current with variable output voltages ranging from +1.3V to +3.3V. (added 3/05)

Dual Monolithic Buck Regulator Provides Two 1.4A Outputs with 2-Phase Switching to Reduce EMI: DN305 - Design Notes (Linear Technology) (app note added 1/06)

EP48 12 V 1.44 W Non-Isolated Buck Converter: This design kit is a non-isolated 12 V, 120 mA power supply utilizing a LNK304. This power supply is intended as a general purpose evaluation platform for LinkSwitch-TN in a buck converter configuration. (added 7/06)

Extend the input range of a Low dropout regulator: 10/17/02 EDN Design Ideas / (added 1/05) Because of process limitations, all ICs have an input-voltage limitation. This limitation can be cumbersome when you try to step down a high supply voltage to a lower, regulated voltage using a dc/dc converter, such as a linear regulator. Adding a FET to the input of a linear regulator creates a dc/dc converter with a wider input-voltage range than the range of the regulator alone....

Flyback LDO Buck Sync. Buck Reference Design: Flyback, LDO, Buck and Sync Buck with Vin 10 to 16 V. Multiple output voltages of -24 V, -5 V, 1.5 V, 3.3 V, 5 V, 12 V and 58 V. The total output power is 15 W. (added 3/05)

Get Buck boost Performance from a Boost regulator: 07/11/02 EDN Design Ideas / (added 1/05) The SEPIC (single-ended, primary-inductance-converter) topology is generally a good choice for voltage regulators that must produce an on output voltage that falls in the middle of the input-voltage range, such as a 5V output from a 2.7 to 6V input, The topology has some disadvantages, however. The efficiency of a SEPIC circuit fares worse than that of buck and boost regulators, and SEPIC desig......

High Current Step-Down Controller Regulates to 0.6V Output from 3V Input: DN322 - Design Notes (Linear Technology) (app note added 1/06)

High Efficiency Monolithic Buck Converter [LTC1265]: DN105 - Design Notes (Linear Technology) (app note added 6/06)

High Power Synchronous Buck Converter Delivers Up to 50A: DN156 - Design Notes (Linear Technology) (app note added 1/06)

High Voltage Buck Regualtors provide High Current Low Profile Power Solutions for FireWire Peripherals: DN287 - Design Notes (Linear Technology) (app note added 6/06)

High Voltage Current Mode Step-Down Converter with Low Power Standby Capability: DN383 - Design Notes (Linear Technology) (app note added 6/06)



High Voltage Low Noise Buck Switching Regulator [LT1777]: DN212 - Design Notes (Linear Technology) (app note added 1/06)

Hot Swap Push-Pull Sync. Buck Negative Flyback Dual Sync. Buck Reference Design: Hot Swap, Push Pull, Sync. Buck, Negative Flyback, Dual Sync. Buck with Vin of -36 V to -72V. Vout of 8 V, 5 V, 3.3 V, 2.5 V and -5 V. The output power is 79.5 W. (added 3/05)

IRDCiP1202-A 300kHz Dual 15A 5.5VIN to 13.2VIN Dual Output Synchronous Buck Converter using iP1202: This board allows engineers to easily evaluate the iP1202 in an independent and parallel configuration that is capable of providing up to 15A per phase with double-sided heat sinking. (added 6/06)

IRDCiP2001-A 500kHz 40A 2-phase Synchronous Buck Converter using iP2001: This board enables engineers to easily evaluate the iP2001 in a 2-phase configuration that is capable of providing up to 40A in a lab environment without airflow. (added 6/06)

Isolated Converters Have Buck Simplicity and Performance: DN377 - Design Notes (Linear Technology) (app note added 1/06)

LDO Buck/Boost 2 Sync Buck Sync Boost Reference Design: LDO, Buck/Boost, 2 Sync. Buck, Sync. Boost with Vin 2.7-4.2 V LiION or 4.5-6.5 V adapter. Multiple output voltages of 1.5 V, 2.5 V, 3.3 V and 8 V. The total output power is 5.5 W. (added 3/05)

LED Buck PFM: Powers LED with Constant Current Starting at 100MV over VF: This is a proof of concept circuit which needs improvement. The part values shown will run a high efficiency red LED with a Vf of 1.9V from only 2 nicads, right down to 2 volts. For a white LED you will need more batteries and you must increase the 1.0K resistor to a higher value. Current sensing at a mere 18mV over 1ohm makes this stepdown switcher efficient, but efficiency can be increased by using a larger inductor, improving transistor switching speed, or by increasing the value of the 1.0K resistor. ... (added 2/05)

LED Headlamps : This article includes circuits of DC-DC LED drivers step downs to run LEDs on less than Battery Volts, Boost for above. (added 4/02)

LM2675 5.0EVAL 1 Amp Step Down High Efficiency Simple Switcher Evaluation Board: National Semiconductor Application Note 10 Feb1999 (app note added 7/02)

Low EMI Synchronous DC/DC Step-Down Controllers Offer Programmable Output Tracking: DN382 - Design Notes (Linear Technology) (app note added 1/06)

Lower DC/DC Converter Ripple by using Optimum Capacitor Hookup: 10/31/02 EDN Design Ideas / (added 3/05) Low-ripple-voltage positive-to-negative dc/dc converters find use in many of today's high- frequency and noise-sensitive disk drives, battery-powered devices, portable computers, and automotive applications. Like a positive buck converter, a positive-to-negative converter can have low output-ripple voltage if you place the bulk input capacitor between VIN and VOUT rather than between VIN and gr......

LT1074/LT1076 Design Manual: AN44 - Linear Technology - This note discusses the use of the LT1074 and LT1076 high efficiency switching regulators. These regulators are specifically designed for ease of use. This application note is intended to eliminate the most common errors that customers make when using switching regulators as well as offering insight into the inner workings of switching designs. There is an entirely new treatment of inductor design based upon simple mathematical formulas that yield direct results. There are extensive tutorial sections devoted to the care and feeding of the Positive Step- Down (Buck) Converter, the Tapped Inductor Buck Converter, the Positive-to-Negative Converter and the Negative Boost Converter. Additionally, many troubleshooting hints are included as well as oscilloscope techniques, soft-start architectures, and micropower shutdown and EMI suppression methods.

LT1777 High Voltage Low Noise Buck Switching Regulator: DN212 - Design Notes (Linear Technology) (app note added 1/06)

Monolithic Step-Down Regulator Withstands the Rigors of Automotive Environments and Consumes Only 100µA of Quiescent Current: DN378 - Design Notes (Linear Technology) (app note added 6/06)

Monolithic Synchronous Step-Down Regulators Pack 600mA Current Rating in a ThinSOT Package: DN300 - Design Notes (Linear Technology) (app note added 6/06)

No Design Switching Regulator 5V 5A Buck (Step Down) Regulator: DN48 - Design Notes (Linear Technology) (app note added 1/06)

Notebook Power Supply has Two Outputs: 03/03/94 EDN-Design Ideas / (added 3/06) The notebook-computer supply in Fig 1 powers the 5V logic and derives an adjustable -24V supply for an LCD's backplane. The design uses only a high-efficiency buck regulator (Si9150) and an NMOS/PMOS, dual-power-FET chip set (Si9943), eliminating the extra parts required when you implement both supplies independently. Because of the low on-resistances of the dual FETs, this circuit can achieve better than 92% efficiency at 7.2V input and full-load output (7.6W)....

Obtain higher Voltage from a Buck regulator: 05/29/03 EDN Design Ideas / (added 1/05) Several semiconductor vendors'current-mode buck controllers have input-voltage ranges of 30 to 36V but have output-voltage ranges from the reference voltage to approximately 6V. This output-voltage constraint arises from the common-mode-voltage limitation of the current-sense amplifier. In real-world applications, the power-supply designer must be able to generate high output voltage for printe......

Off Line Buck Regulator Cuts Costs Leadtime: 10/26/95 EDN-Design Ideas / (added 3/03)

Positive regulator makes negative DC/DC converter: 12/26/02 EDN Design Ideas / (added 1/05) Power-supply designers can choose from a plethora of available positive buck regulators that can also serve as negative boost dc/dc converters. Some buck regulators have a negative-feedback reference voltage expressly for this purpose, but ICs that have positive-reference feedback voltages far outnumber these negative-feedback regulators....

Power Management in Portable Applications: Understanding the Buck Switchmode Power Converter: Microchip Application Note - Published 18-Jul-01 (app note added 2/06)

Interface Cable for Casio Qv-200 Digital Camera: (electronic circuit added 4/05)

Kodak DC 20 Camera Interface (PIC12C509): (circuit / schematic design added 6/06)

Lightning Activated Camera Shutter Trigger: This circuit is used to trigger a camera's electronic shutter circuit when a flash of lightning is present. This circuit would also work for photographing fireworks displays or other events involving flashes of light. (added 10/05)

Adjustable Strobe Light: 120-Volt mains power source, up to20 Hz flash rate (added 4/02)

Flash Slave Trigger: Flash slaves are used when you need to supplement1-flash unit with1-or several more. This slave trigger simply triggers those other units. It does this by "seeing" the first flash (using a phototransistor) and triggering the other flashes a few microseconds later. The sensitivity of the circuit is adjustable to compensate for ambient light or dimmer than usual master flashes. (added 5/02)

LX1995 LED Driver: Camera Flash Application (AN-30): Application Note 30 from Microsem (app note added 6/06)

Miniature Strobe Light: (electronic Circuit / Schematic added 10/04)

Mini Pocket Strobe Circuit: works from two1.5-Volt AA batteries, based on modified camera flash unit (added 6/03)

Audio Acquires the Write touch: 02/20/03 EDN-Design Ideas / (added 11/05)

Capacitance Meter #1: (Circuit added 9/04)

Capacitance Meter #2: (added 8/03)

AN-829: Environmental Compensation on the AD7142: The Effects of Temperature and Humidity on Capacitance Sensors: AN-829 - Analog Devices Application Notes (Circuit / schematic design added 6/06)

Dual Comparators Stabilize Proximity Detector: 02/16/98 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)

Measure open circuited cables using a multimeter: 09/26/02 EDN Design Ideas / (added 1/05) You can use a multimeter with capacitance-measurement capability to measure the length of wire or cable to an open circuit. The capacitance of a pair of wires (or a wire to a shield) is directly proportional to the length of the wire. If you know the capacitance per foot of wire, then you can calculate how far it is to the open circuit....

Touch Activated Alarm: (added 10/02)

Using the AD7142 and a Capacitive Sensor to Develop a Single-Push Digital Shutter Button: AN-833 - Analog Devices Application Notes (added 2/06)

Fastest Finger First Indicator: (electronic Circuit / Schematic added 10/04)

Touch Activated Alarm (uoguelph_: (schematic / circuit added 10/02)

Touch Activated Lamp (ourworld): (circuit / schematic design added 6/06)

Touch Dimmer: (electronic Circuit / Schematic added 10/04)

Touch Switch Needs No DC Return Path: 02/03/05 EDN Design Ideas / (added 5/05) Common designs for touch switches detect a decrease in resistance when a user's fingertip either connects a contact to the circuit's common ground or supplies an injection of 60-Hz ac voltage, resulting from immersion in the electrostatic field that nearby power lines radiate. But what if no nearby power lines exist and the equipment operates from a battery source, such as in an automotive appl...

Ultracapacitor powers bicycle light: 09/28/00 EDN Design Ideas / (added 2/06)

Solar Cells implement Low Cost Illuminator: 09/12/97 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)

Memory termination IC balances charges on series capacitors: 08/18/05 EDN Design Ideas / (added 11/05) Get the best performance from high-value capacitors with simple IC circuit.

Mains Remote Alert: Remotely-operates a Beeper and/or a LED via mains supply line Simple Circuitry, easy to build unit (Circuit added 9/04)

Single NiCd Cell Drives OpAmp: 12/05/96 EDN-Design Ideas / (added 2/06)

Wireless Microphone #4: (Electronic circuit added 4/05)

Miniature MW Transmitter: circuit diagram of simple medium wave transmitter using BF494B. This simple transmitter have a range of 200 meters. . (Circuit added 9/04)

Miniature FM Transmitter #1: (Electronic Schematic / circuit added 4/02)

Miniature FM Transmitter #2: (Electronic Schematic / circuit added 4/02)

Miniature FM Transmitter #3: (Electronic Schematic / circuit added 4/02)

Selecting Inductors for Buck Converters: National Semiconductor - Application Note (app note added 7/06)

'Shoot-through' in Synchronous Buck Converters / AN-6003: Fairchild Application Notes / (app note added 6/06)

Simple Sychronous Buck Regulator: MCP1612: Microchip Application Note - Published 14-Jan-05 (app note added 2/06)

Solar Step Down Regulator: (Circuit / schematic design added 6/06)

ST1S03 buck converters for hdd power supplies: AN2093 2. INTRODUCTION Purpose of This AppNote is to provide a brief summary of the specifications and the functionality of the application board.... (app note added 7/06)

Stepdown converter uses a ceramic output capacitor: 06/07/01EDN-Design Ideas / (added 7/03)

Sychronous Buck Regulator: MCP1612: Microchip Application Note - Published 14-Jan-05 (app note added 2/06)

Sync. Buck with Integrated FET Forward Dual Sync. Buck Reference Design: Sync. Buck with Integrated FET, Forward, Dual Sync. Buck with Vin of 48. Vout of 15 V, 3.3 V, 1.8 V, 1.5 V. The output power is 47 W. (added 6/06)

Synchronous Buck circuit produces negative Voltage: 02/06/03 EDN Design Ideas / (added 1/05) Many electronic systems require both positive and negative voltages to operate properly. Generating an efficient, low-voltage positive output from a higher voltage input typically entails the use of a synchronous buck regulator. But when generating a negative output voltage from a positive input voltage, you'd typically use a flyback topology, especially at higher output currents....

Synchronous buck MOSFET loss calculations with Excel model / AN-6005: Fairchild Application Notes / (app note added 6/06)

Synchronous Buck Reference Design #2: This reference design is synchronous buck-boost converter that can deliver up to 3.8 A of continuous current at -5 V from a 5 V input. This topology uses a synchronous buck controller (TPS5103) referenced to the negative output rail. The synchronous MOSFETs allow this design to achieve a peak efficiency of 88%. In addition, the TPS5103 provides a soft-start function and over-current protection. (added 3/05)

Synchronous Buck Reference Design: This reference design is a 5Vdc input to 1.65V @ 1A output synchronous buck converter. The controller is the TPS40003 operating at 600KHz. The controller features Predictive Gate Drive, which minimizes the bottom FET body diode conduction time. This provides the benefit of increased efficiency when compared to a standard gate drive method. Very low output ripple voltage and excellent transient load performance are achieved with this design. (added 3/05)

Synchronous Flyback Circuit Provides High Efficiency Conversion: 07/22/04 EDN Design Ideas / (added 1/05) Buck regulators are usually the first choice when you design nonisolated step-down regulators unless the ratio of VIN to VOUT is greater than 10, the input voltage is high, or both. Low duty cycle can be problematic for FET drivers and cause current-mode control loops to lose control. Efficiency can fall dramatically to 60 to 70% at low VOUT and current of only a few amps.

ThinSOT Micropower Buck Regulator has Low Output Ripple: DN373 - Design Notes (Linear Technology) (app note added 6/06)

Three parts provide tenfold increase in Switcher Current: 08/22/02 EDN Design Ideas / (added 1/05) Industrial-control circuits often derive their power from widely varying sources that can exceed the 40V maximum rating of popular switching ICs. This Design Idea presents a simple, flexible, and inexpensive buck switcher that converts an input voltage as high as 60V to 5V at several amps. The circuit is unique in that it boosts current with almost no compromise in performance, size, or cost....

Tiny Buck Regulator Accepts Inputs from 3.6V to 25V and Eliminates Heat Sink: DN268 - Design Notes (Linear Technology) (app note added 6/06)

Tiny Step-Up/Step-Down Power Supply Delivers 3.3V at 1.3A in Battery-Powered Devices: DN271 - Design Notes (Linear Technology) (app note added 1/06)

Tiny Versatile Buck Regulators Operate from 3.6V to 36V Input: DN367 - Design Notes (Linear Technology) (app note added 6/06)

TSM108 Evaluatin Board 12V to 6V DC/DC Converter: The TSM108 is a step down controller that features constant voltage and constant current regulation.The Evaluation Board was designed to allow different converter configurations. Several options for power semiconductor footprints are available on the PCB in order to make it adaptable to a wide range of converter output power. In a first step, this application note will describe the typical application. Then the various options available on the Evaluation Board PCB will be explained. (app note added 6/06)

Two AA cells power step down regulator: 01/07/99 EDN-Design Ideas / (Schematic / circuit added 10/02) [Note: File contains multiple circuits - scroll to find this circuit] DC/DC conversion is particularly challenging when both the input and output voltages are low. Step-up ICs that operate with inputs lower than 1V are available, but step-down ICs that accept input voltages near 2V are not. Thus, providing efficient power for the low-voltage CPU in a handheld product can be a problem if the power source is a two-cell AA battery.....

Wide range regulator delivers 12V 3A output from 16 to 100V source: 06/23/05 EDN Design Ideas / (added 10/05) Buck regulator tackles high input voltages.

Wide-Input, High Voltage Buck Converter: National Semiconductor - Application Note (app note added 2/06)

Insect Repellant: (electronic design added 10/06)



Insect Repellant: (circuit / schematic added 2/03)



Mosquito Repellant: (added 9/02)



12C508 Smart Lock: base sends a data sequence ( password) which is recognized by key. key checks sequence and -if it recognizes it -sends to base anor data sequence, as an answer to password. At Time when base gets a correct answer (which means that key has been introduced), relay is put into action, and it can command a number of consumers. (added 4/02)

4 Digit Keypad: (circuit design added 8/03)

5 Zone Alarm Circuit: (design circuit added 8/02)

6A door lock motor driver for automotive: AN456AN456AN456AN456AN456 nal (OVV), put at low level enable of L9937, confirming hardware switch-off of motor ; in this condition an output of half bridge is in... (app note added 6/06)

Alarm Control keypad: (circuit design added 8/03)

Almost Ultrasonic Motion Sensor: (circuit design added 8/03)

Analog Video Router: Intersil Application Block Diagram (app note added 6/06)

Anti Theft Motorcycle Alarm: (electronic design added 9/02)

Anti-Bag-Snatching Alarm: (electronic Circuit / Schematic added 10/04)

Anti-Theft Alarm for Bikes: (electronic Circuit / Schematic added 10/04)

Anti-Theft Security for Car Audios: (electronic Circuit / Schematic added 10/04)

Automatic door opener with PIC12C508: This circuit can be used to operate an electric strike or an electromagnetic lock on a door. It is not door being opened/closed, but a small electromagnetic strike which unlocks door…. (added 4/05)

Basic RF Transmitter for PIR Sensors: (circuit design added 8/03)

Combination Lock: This circuit is very basic to build. To open a the lock which is connected to the K1 Load. you must press each momentary switch in the correct sequence. The sequence used in this circuit is S1,S2,S3,S4. If any of the other switches are pressed the circuit will reset and you will need to start over. Depending on how you wire the switches, you can use any4 switch combination (added 2/03)

Combination Lock (PIC16F84): (circuit design added 8/03)

Cut Phone Line Detector #1: Can be used to alarm security system (added 4/02)

Digital Combination Lock: (electronic design added 9/02)

Digital Electronic Lock: (electronic (schematic / circuit added 11/05)

Door/Window Sensor Resists Tampering: 01/21/99 EDN-Design Ideas / (added 11/05) The simple, inexpensive circuit in Figure 1 detects a failure (or deliberate tampering) on lines connected to normally closed switch sensors. For example, common door interlocks and door/window sensors consist of normally open or normally closed magnetic reed switches. Depending on the monitoring configuration, an open or short on a line may go undetected, thus preventing alarm activation. Embedding a resistor in a normally closed sensor and using bipolar dc power supplies produces the balanced configuration in Figure 1. A short or open on a line (or sensor activation) produces a net positive or negative voltage at the input of the Q1-Q2 pair....



C

AN34 ZXSC100 Power Supply for Digital Still Camera: Zetec Semiconductors Applications Notes Presented in this applications note is a typical sytem power supply design for a digital still camera. The solution is based on ZXSC100 DC-DC boost converter which provides an efficient and cost effective design. Conversion is from a two cell alkaline battery, 3V to 2V, to a regulated 3.3V output with a maximum load current of 100mA. All performance graphs associated with this design are provided in application note. (app note added 2/06)

Automatic -Exposure Scheme uses Ccd Shutter : 07/02/98 EDN-Design Ideas / (added 11/05) This application follows Design Idea, "Peak detector maximizes CCD-sensor range" (EDN, Aug 15, 1996). Its aim was to optimize performance of an A/D converter used to digitize a linear CCD sensor's analog output. The method involved stretching upper reference of flash ADC....

Camera Power and Video Use Same Coax Cable : 09/25/97 EDN-Design Ideas / (added 2/06)

Casio QV-200 Digital Camera Cable. : Lose your cable? Build it yourself and save $29. Fits many QV models. (added 6/06)

Debugging an MCU-based CCD camera controller: Agilent Application Note (app note added 6/06)

Miniature FM Transmitter #4: (add 9/04)

Cellular Phone Helper #2: (Circuit / schematic design added 6/06)

AN-42036 / PCB Grounding System and FAN2001/FAN2011 High Performance DC-DC Converters: Fairchild Application Notes / (app note added 6/06)

5V Power Supply Teams Low Dropout Regulator Charge Pump: 01/08/04 EDN Design Ideas / (added 1/05) Auxiliary power of 3.3V is replacing 5V auxiliary power that "silver boxes" supply in most computer systems, but some circuits still require a 5V supply. Such systems impose messy task of creating a central 5V auxiliary....

AN-348: Avoiding Passive-Component Pitfalls: AN-348 Analog Devices Application Note (app note added 2/06) The Wrong Passive Component Can Derail Even Best Op Amp or Data Converter. Here Are Some Basic Traps to Watch For.

Avoiding Passive-Component Pitfalls: AN-348 Analog Devices Application Note (app note added 2/06) The Wrong Passive Component Can Derail Even Best Op Amp or Data Converter. Here Are Some Basic Traps to Watch For.

Build a Charge Pump with UltraLow Quiescent Current: 09/05/04 EDN Design Ideas / (added 1/05) Portable battery-powered devices often spend most of ir life in standby mode, in which quiescent current of an internal boost converter continuously bleeds battery. The quiescent current during standby can be larger than actual load current......

Charge Pump Doubles Negative Voltage: Maxim App Note #782 (app note added 7/03)

Compact Inductorless Boost Circuit Regulates White LED Bias Current: Maxim Application Note #1116 (app note added 7/03)

Controlling a Variable Voltage Power Supply using the DS1809 (Pushbutton Control): Maxim Application Note #1035 (app note added 7/03)

AN-79: IC PreAmplifier Challenges Choppers on Drift: National Semiconductor - Application Note (Circuit / schematic design added 6/06)

Chopper Amplifiers Complement a DC Accurate Low-Pass Filter: DN9 - Design Notes (Linear Technology) (Circuit / schematic design added 6/06)

Chopping Reduces Reference’s Supply Current: 04/10/97 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)

Ultra Low Noise Op Amp Combines Chopper and Bipolar Op Amps: DN36 - Design Notes (Linear Technology) (added 2/06)

100 MHz Clock Solution for Desktop Computers: Pericom Semiconductor Application Brief # 021 (app note added 2/05)

68HC11 Stepper Motor Control: (circuit / schematic design added 6/06)

72 LED Clock: (electronic Circuit diagram added 03/03)

74ACT74 Makes Low-Skew Clock Divider: 12/17/98 EDN-Design Ideas / (added 11/05) Serial-data systems often generate an internal clock at twice data rate for mid-bit sampling or for generating bi-phase codes. External equipment and some internal processes require a clock that runs at data rate. Simply dividing twice-rate clock with a flip-flop generates a data-rate clock that is skewed by one logic delay with respect to input.....

AD9430 Evaluation Board Modifications for XTAL Oscillator Clocking: AN-616 Analog Devices Application Notes (app note added 6/06)

AN-291: Asynchronous Clock Interfacing with the AD7878: AN-291 Analog Devices Application Notes (app note added 6/06)

AN-616: AD9430 Evaluation Board Modifications for XTAL Oscillator Clocking: AN-616 Analog Devices Application Notes (app note added 6/06)

AN-657: ADN2812 Evaluation Board: AN-657 Analog Devices Application Notes (app note added 2/06)

AN-769: Generating Multiple Clock Outputs from the AD9540: AN-769 Analog Devices Application Notes (app note added 2/06)

Application of Zero-Delay Buffers in Switched Ethernet: Pericom Semiconductor Application Note # 015 (app note added 02/05)

Binary Coded Decimal (BCD) Clock (circuitdb): The clock circuit above uses seven ICs and 19 LEDs to indicate binary coded decimal time. The LEDs can be arranged (as shown in example above) so that each horizontal group of 3 or 4 LEDs represents.... (added 2/07)



Cheap 40kHz Clock: (electronic circuit added 7/03)

Chester's Propeller Clock: (design added 10/06)

Clock Recovery Scheme Suits Low Snr Systems: 06/05/00 EDN-Design Ideas / (added 6/06) A clock-recovery architecture can operate with NRZ digital signals, even at low SNRs. A clock-recovery subsystem is based on a PLL comprising a phase comparator, a loop filter, and a voltage-controlled oscillator (VCO)....

Clock Performance in Raid Storage Applications: PI6c2502: Pericom Semiconductor Application Note # 026 (app note added 02/05)

Clock Termination Techniques: Pericom Semiconductor Application Brief # 023 (app note added 02/05)

Crystal Considerations with Dallas Real-Time Clocks (RTCs): Maxim Application Note #58 (app note added 2/05)

Crosstalk on the Clock (Part 2): Maxim Application Notes / 1841 / Nov-04 (app note added 6/06)

ADN2819 Evaluation Board: AN-636 Analog Devices Application Notes (app note added 2/06) This application note describes use of ADN2819 evaluation board. The ADN2819 is a multirate clock recovery, data-retiming device based on a multiloop PLL architecture…..

Morse Code Practice Keyer #1: (added 10/02)

Morse Code Practice Keyer #2: (added 10/02)

30 Meter QRP Transmitter for Morse Code: (Circuit / schematic design added 6/06)

Morse Paddle Keyer: (Electronic circuit added 4/05)

Touch CPO: touch operated code practice oscillator using popular timer IC555. Practice Morse code in a different way. . (Circuit added 9/04)

Two Way Morse Practice Set: (added 2/05)

Color Organ #1: make different colored bulbs light at different frequencies of music, connects to speaker outputs (added 4/02)

Color Organ #2: one lamp color organ (added 4/02)

Color Organ #3: makes3 Light to blink and flash to music (added 7/03)

Colour (Sound) Organ: (electronic circuit added 4/05)

Simple Colour Organ: (electronic circuit added 4/05)

Wide Swing Variable Crystal Oscillator: (added 2/05)

4 Transistor Transmitter: (added 8/03)

Crystal Oscillators and Frequency Multipliers using the NE602 and NE5212: Philips Semiconductors Application Notes 1983, December 1991 (Electronic circuit design added 02/05)

LC (Colpitts) Oscillator operates on 0.5V to 5V Single Supply: Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc. (Circuit / schematic design added 6/06)

NanoPower LC (Colpitts) Oscillator Circuits: Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc. (Circuit / schematic design added 6/06)

Positive Feedback: The use of positive feedback is useful for producing oscillators. The condition for positive feedback is that a portion of the output is combined in phase with the input. For an amplifer with positive feedback the gain is given by the expression below. (Electronic circuit design added 02/05)

Trimless IF VCO part 2: Maxim Application Note 688, February 5, 2001 (Electronic circuit design added 02/05)

Resonant Frequency of a Colpitts Oscillator: (Electronic circuit design added 02/05)

Use of the CMOS Unbuffered Inverter in Oscillator Circuit: Texas Instrument Application ReportSZZA043 January 2004 (Electronic circuit design added 02/05)

AN17 Emergency Lighting Systems and Battery Powered Fluorescent Lighting: High Current To92 Switching Transistors Provide 87% DC-AC Conversion Efficiency: Zetec Semiconductors Applications Notes An overview of principles behind typical emergency lighting systems, fluorescent tube behaviour, and requirements of transistors for efficient voltage inversion. The note also includes two "Royer" based designs for low voltage systems. (app note added 6/06)

Bidirectionall Power Inverter: (circuit added 1/07)

Choosing DACs for Direct Digital Synthesis: AN-237 Analog Devices Application Notes (app note added 6/06)

DAC ICs: How Many Bits Is Enough?: AN-327 Analog Devices Application Notes (app note added 6/06) Digital audio playback DACs are available in a variety of different architectures--each with it's own performance tradeoffs.



DC/AC Inverter (interq): (electronic circuit added 4/05)

DC/AC Inverter (interq): (electronic circuit added 4/05)

Resistance, DC Current, AC Current, Frequency and Period Measurement Errors in DMMs (5988-5512EN): Aligent Application Note (added 4/08)

+5 to-15 Volts DC Converter: National Semiconductor - Application Note (app note added 2/06)

+30V Power Supply with +5V: I made the power supply which makes about +30V with +5V power supply. 
The direct current is changed into the alternating current by the oscillator which used the schmitt trigger inverter which has the hysteresis characteristic and the resonance circuit. The high DC voltage (+50V) is made with the alternating voltage using the voltage amplification rectification circuit. (app note added 6/06)

1.3V Power Supply: This is a replacement power source for 1.3V mercury cells or other small batteries. It has many uses and I use this circuit in my computer to power a front panel multi adapter which has a digital thermometer. (added 6/06)

3.3V lithium cell supply requires one inductor: 08/05/99 EDN - Design Ideas / (added 09/05) Because of the growing popularity of lithium-ion (Li-ion) batteries and 3.3V power supplies, portable-equipment designers must often create a 3.3V supply that a single Li-ion cell can power. The fact that the output of a Li-ion battery ranges above and below 3.3V during its discharge cycle complicates the design.

48kw Resonant Converter for X-Ray Machines Uses High Speed Power Modules With Integral Liquid Cooling: This paper describes an innovative method for the removal of heat from the four IGBT power modules equipping a 48kW ZVS-mode resonant power converter for CT X-ray machines. Application Note Microsemi APT9904 ( app note added 4/08)

6 to 12 Volt Converter: This circuit can provide up to 800mA of12V power from a 6V supply. The circuit is simple, about 75% efficient and quite useful. (added 4/02)

9-V Stabilized Power Supply: (added 2/06)

60V Step-Down DC/DC Converter has Only 100µA Quiescent Current: DN1007 - Design Notes (Linear Technology) (app note added 1/06)

+/-5V Power Supply Operation with TC7106A/7107A (TC7106A/7107A): Microchip Application Note - Published 12-Nov-02 (app note added 6/06)

Avoiding Passive-Component Pitfalls: AN-348 Analog Devices Application Notes (app note added 2/06) The Wrong Passive Component Can Derail Even Best Op Amp or Data Converter. Here Are Some Basic Traps to Watch For.

Analog Signal-Handling for High Speed and Accuracy.: AN-342 Analog Devices Application Notes (app note added 2/06)

Crystal Controlled Time Base Generator: (Electronic Circuit / Schematic added 10/04)

Crystal Oscillator overcomes typical Drawbacks: 08/17/98 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)

JT-11ssp 6m as Input Transformer for Crystal Cs5367 A/D Converter: transformer balanced passive input circuit for CS5367 A/D converter, PDF file (Circuit / schematic design added 6/06)

Specifying Quartz Crystals: Maxim Application Notes / 726 / Dec-08 (Circuit / schematic design added 6/06)

Study of the Crystal Oscillator for CMOS CoPS: National Semiconductor Application Note 04 Nov1995 (circuit / schematic added 2/03)

Use of the CMOS Unbuffered Inverter in Oscillator Circuit: Texas Instrument Application ReportSZZA043 January 2004 (Electronic circuit design added 02/05)

Ultra Low Voltage Micropower Crystal Oscillator Circuit: Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc. (Circuit / schematic design added 6/06)

Analog multipliers take cube roots: 4/10/97 EDN-Design Ideas -- (electronic circuit added 5/'02)



13.8 Volt 20psu: This is a Regulated DC power supply with short circuit protection and with current limiter. (added 6/03)

Add-on Current Limiter: With buzzer (circuit added 11/06)

Circuit Provides Hiccup Current Limiting: 06/26/03 EDN Design Ideas / (added 1/05) Current-limit protection is an essential feature for power-supply systems. The three major types of current-limit-protection mechanisms are constant, foldback, and hiccup. Hiccup current limit performs the best of the three types; however, the implementation is rather complex. In this scheme, upon detection of an overcurrent event, the whole power supply shuts down for an interval before it tri......

Current-Limit Switch is Digitally Programmable: 08/17/00 EDN-Design Ideas / (added 2/06)

L200 Psu: easy to power supply with1-single L200 IC, offers a variable current limit of up to2 A, as well as voltage regulation (added 10/05)

Voltage Reference sets Current limit : 11/19/98 EDN-Design Ideas / (added 6/06)

4 to 20 Mloop Needs No External Power Source: 09/13/2001 EDN - Design Ideas / (Electronic circuit design added 02/05) The simple circuit in Figure 1 uses a low-current-drain MAX4073H amplifier to sense the current flowing through a 4- to 20-mA loop. The circuit senses the current through a 1Ω resistor with a fixed gain of 100 and uses no battery or dc power supply. The low current drain of the amplifier (0. .

Loop powers Current transmitter: 10/28/99 EDN-Design Ideas / (added 2/06)

Circuit forms novel floating current source: 05/01/03 EDN Design Ideas (added 1/05) Figure 1 shows a polarization circuit applicable to ISFET (ion-sensitive field-effect-transistor) sensors. ISFETs are solid-state chemical sensors that measure the pH value of a solution in biomedical and environmental applications, for example. The circuit in Figure 1 is extremely simple; it sets fixed-bias conditions for ISFET sensors (VDS=I0 RX; IDS=I0)....

A Simple Current-Sense Technique Eliminating a Sense Resistor (AN-7): Application Note 7 from Microsem (Circuit / schematic design added 6/06)

AN-D16: Lnd1 Series: Constant Current Sources And: Supertex Semiconductors (app note added 2/06)

AN-D18: Dn25 Series: Constant Current Sources And: Supertex Semiconductors (app note added 2/06)

Cascode Current Source : Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc. (Circuit / schematic design added 6/06)

Constant Current Battery Charger: (circuit added 7/02)

Current Source and Sink Circuits Have Low Tc: 07/04/96 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)

Current Source Multiplication: Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc. (Circuit / schematic design added 6/06)



D



A Closer Look at LVDS Technology: Pericom Semiconductor Application Note # 041 (Circuit / schematic design added 6/06)

An introduction to the CAN protocol that discusses the basics and key features.: Microchip Application Note - Published 16-Sep-05 (Electronic Circuit added 03/06)

AN-1074: CAN Products from National Semiconductor Users Guide and Application Note: National Semiconductor - Application Note (Electronic Circuit added 03/06)

AN515: Communicating with IIC Bus using PIC16c5x: Microchip Application Note - Published 26-Aug-97 (Electronic Circuit added 03/06)

AN971: USB Port-Powered Li-ION/Li-Polymer Battery Charging: Microchip Application Note - Published 31-Jan-05 (Circuit / schematic design added 6/06)

Design a Low Jitter Clock for High Speed Data Converters: Maxim Application Notes / 800 / Aug-05 (Circuit / schematic design added 6/06)

Design a Visible Optical Link for RS 232C Communications: 01/09/03 EDN Design Ideas / (Electronic Circuit added 03/06) The design in Figure 1 is a visible optical link for those who need to see the transmitted data. An isolation figure of more than 5000V is a bonus. Tests of the system used the COM input of a data-acquisition system, as well as a standard PC's COM port. The MC1489 converts the RS-232C data to TTL signals....

DS92LV010A Bus LVDS Transceiver Ushers in a New Era of High-Performance Backplane Design: National Semiconductor - Application Note (Circuit / schematic design added 6/06)

DS92LV010A Bus LVDS Transceiver Ushers in a New Era of High-Performance Backplane Design: National Semiconductor - Application Note (Circuit / schematic design added 6/06)

CA3090 Stereo Decoder: Stereo Multiplex Decoder (circuit added 8/06)

LM1310 FM Stereo Decoder: Converts your mono FM Receiver to Stereo (circuit added 8/06)

LM1800 Stereo Demodulator: Phase-Locked Loop FM Stereo Demodulator (circuit added 8/06)

Remote Control Encoder/Decoder with PIC16c620 and PIC12c508: (circuit / schematic design added 6/06)

Use Your Printer Port as a High Current Ammeter: 07)/06/00 EDN-Design Ideas / (added 7/03) -With a few inexpensive components and INT1Ch, you can turn the printer port of your PC into a high-current ammeter....

High and Low Voltage Cutout with Delay and Music: Voltage variations and power cuts adversely affect various equipment such as TVs, VCRs, music systems and refrigerators. This simple circuit will protect the costly equipment from high as well as low voltages and the voltage surges (when power resumes). It also gives a melodious tune when mains power resumes. When mains voltage is normal,..... (added 10/05)

Feedback Circuit Eliminates CCD Driver Delay Mismatch: 09/18/03 EDN Design Ideas / (added 1/05) In a CCD (charge-coupled device), packets of charges shift across the array. The transistor array, also called a bucket-brigade shift register, receives drive from a dual-phase clock signal. Dual-phase clock signals comprise two synchronized clock signals that are 180° out of phase. High peak-output-current CCD drivers can buffer the logic-level clock signals and turn them into high-voltag......

Delay Line Implements Clock Doubler: 07)/18/96 EDN-Design Ideas / (added 3/03)

Butterworth Filter has Adjustable Group Delay: 08/08/02 EDN Design Ideas / (added 1/05) The Sallen-Key realization of a 5.25-MHz, three-pole Butterworth filter has a gain of 2V/V and can drive 75Ω back-terminated coax with an overall gain of 1 (Figure 1). Used to reconstruct component-video (Y, Pb, Pr) and RGB signals, this filter has an insertion loss greater than 20 db at 13.5 MHz and greater than 40 db at 27 MHz (Figure 2)....

Spread Spectrum Method Identifies Audio Path: 04/13/00 EDN-Design Ideas / (added 8/04) An unusual method of audio spread spectrum can identify the audio path that's currently in use through a consumer-electronic device. The design in Figure 1a uses an injected audio spread-spectrum tag signal because a listener does not notice the low...

Inverted Bipolar Transistor Doubles as a Signal Clamp: 11/09/00 EDN-Design Ideas / (Electronic circuit added 7/03) A number of circuits, such as level detectors and AM demodulators, benefit from a rectifier with a low offset voltage....

Demodulator Schematic/Design: The demodulator block diagram below has three major sections that were implemented in this iteration of the design, the mixer, the filter, and the phase shift network (Electronic circuit added 7/03)

Clock Recovery Scheme Suits Low Snr Systems: 06/05/00 EDN-Design Ideas / (Electronic circuit added 7/03) A clock-recovery architecture can operate with NRZ digital signals, even at low SNRs. A clock-recovery subsystem is based on a PLL comprising a phase comparator, a loop filter, and a voltage-controlled oscillator (VCO)....

Ber Meter is Easy to Build: 03/02/00 EDN-Design Ideas / (added 1/06) A bit-error-rate (BER) tester is a basictool for digital-communications measurements. Although many commercial BER testers are available, you can easily design and build an inexpensive version. The scheme in Figure 1 has performance similar to that of a commercial tester but requires you to perform a manual calculation based on displayed data. The tester displays received bits and received erroneous bits, and you must calculate the BER data using a handheld calculator, for example....

1-Wire Humidity Sensor: App Note 758: Maxim IC (application note added6/06)

741 Based Light Sensor: CdS photocell used for light/dark controlled relay (added 4/02)

Measure humidity and temperature on one TTL line: 08/30/01 EDN Design Ideas / (added 1/05) By combining the responses of an Analog Devices (www.analog.com) AD590 temperature sensor and a Humirel (www.humirel.com) HS1101 humidity sensor, you can generate a single TTL-level signal containing information from both sensors (Figure 1). This design uses a 74HC123 monostable multivibrator, IC1, to form a free-running oscillator. ...

Tiny Dew Sensor: (electronic Circuit / Schematic added 10/04)

Dew sensor: Dew (condensed moisture) adversely affects the normal performance of sensitive electronic devices. A low-cost circuit described here can be used to switch off any gadget automatically in case of excessive humidity. At the heart of the circuit is an inexpensive (resistor type) dew sensor element. Although dew sensor elements are widely used in video cassette players and recorders, these may not be easily available in local market. However, the same can be procured from....(added 11/06)

Synthesize Optimal Digital-Frequency Dividers: 05/13/99 EDN-Design Ideas / (added 11/05)

Clock Divider Circuit: (circuit / schematic design added 6/06)

Counter Provides Divide by 45 Function: 05/22/97 EDN-Design Ideas / (added 3/03)

Circuit divides frequency by N+1: 07/11/02 EDN Design Ideas / (added 1/05) Digital frequency dividers usually use flip-flop stages that connect the Q pin to the D data-input pin of the following stage. This configuration creates a binary waveform that you can feed back to the input. You can divide any integer lower than 2N with minimal stages, where N is the number of stages....

Birdie Doorbell Ringer: (schematic / circuit added 10/02)

Ding-Dong Bell: (electronic Circuit / Schematic added 10/04)

Doorbell with Counter: (circuit added 7/02)

Multi-Switch Doorbell with Indicators: (electronic Circuit / Schematic added 10/04)

Ask the Applications Engineer-2: AN-351 Analog Devices Application Notes (app note added 2/06) Trimming Offset and Gain in A/D's and D/A's

AN-711: AD5227 Evaluation Kit for the 64-Position, Up/Down Control Digital Potentiometer: AN-711 Analog Devices Application Notes (app note added 2/06)

AN-642: Coupling a Single-Ended Clock Source to the Differential Clock Input of Third-Generation TxDAC® and TxDAC+® Products: AN-642 Analog Devices Application Notes (app note added 2/06)

AN-420: Using the AD9708/AD9760/AD9701/AD9764-EB Evaluation Board: AN-420 Analog Devices Application Notes (app note added 2/06)

AN-336A: Image Compression-Spelling Out the Options: AN-336A Analog Devices Application Notes (app note added 2/06)

AN-318: AD7528 Dual 8-Bit CMOS Multiplying DAC: AN-318 Analog Devices Application Notes (app note added 2/06) This Application Note details a myriad of circuit applications made possible by multiplying characteristics and/or resistor ladder matching characteristics of AD7528.

AN-310: Single Supply 12-Bit DAC Circuits using the AD7568: AN-310 Analog Devices Application Notes (app note added 2/06)

AN-271: Applying the New CMOS Micro-Dacs: National Semiconductor Application Note (app note added 2/06)

AN-237: Choosing DACs for Direct Digital Synthesis: AN-237 Analog Devices Application Notes (app note added 2/06)

Square Wave to Sine Circuit: (Electronic circuit added 7/03)



+5V Switching regulator (1): (electronic circuit added 2/07)

12 Volt 30 Amp PSU: Using multiple power transistors to increase current of 7812 IC voltage regulator (circuit added 11/06)

2 Watt Switching Power Supply: from 6V to14V (added 4/02)

12 Volt DC to 120 Volt AC Inverter: this inverter should solve that problem. It takes12 VDC and steps it up to120 VAC. -Wattage depends on which transistors you use for Q1 and Q2, as well as how "big" a transformer you use for T1. inverter can be constructed to supply anywhere from1 to1000 (1 KW)-Watts. (added 4/02)AB-11 / PC Board Layout Checklist: DC-DC Converters: Fairchild Application Notes / (app note added 6/06)

AN-348: Avoiding Passive-Component Pitfalls: AN-348 Analog Devices Application Note (app note added 2/06) The Wrong Passive Component Can Derail Even Best Op Amp or Data Converter. Here Are Some Basic Traps to Watch For.

AN-4140 / Transformer Design Consideration for off-line Flyback Converters Using Fairchild Power Switch (FPStm): Fairchild Application Notes / (app note added 6/06)

Boost Controller Drives Buck Converter: 02/03/97 EDN Design Ideas / (added 3/05) -By adding an external Switching Transistor, you can use a step up dc/dc Converter to step down voltages to produce an efficient Battery Powered Power Supply, this example Circuit can step down inputs as Low as2V to Outputs as Low as1.25V, with efficiency as high as 80%

Avoiding Passive-Component Pitfalls: AN-348 Analog Devices Application Note (app note added 2/06) The Wrong Passive Component Can Derail Even Best Op Amp or Data Converter. Here Are Some Basic Traps to Watch For.

Buck/Boost Charge Pump Regulator Powers White LEDs from a Wide 1.6 Volt to 5.5 Volt Input: Maxim Application Note #1021 (app note added 7/03)

Build a Transformerless 12V to 180V DC/DC Converter: 07)/08/04 EDN Design Ideas / (added 1/05) Some transducers for portable or automotive applications need accurately regulated, high-voltage bias and draw little current. To produce such high voltages from a low battery voltage, designers typically use switch-mode dc/dc converters—generally, flyback converters. These converters exhibit high efficiency at medium or high output power.

1 Hz to 100 MHz VFC Features 160 Db Dynamic Range: 9/1/05 EDN Design Ideas / (added 10/06) Transform voltage to current over wide frequency, amplitude.

Photo-Diode Current-To-Voltage Converters: National Semiconductor Application Note (app note added 2/06)

Design Formulas Simplify Classic V/I Converter: 01/20/00 EDN-Design Ideas / (added 7/03)

Voltage-To-Current Conversion Amplifier: How to transform the passive voltage-to-current converter into an active one. (added 4/08)

Voltage to Current Converter Makes a Flexible Current Reference: 09/18/03 EDN Design Ideas / (added 1/05) The voltage-to-current converter in Figure 1 can both source and sink current. The circuit is more flexible than some traditional current references that require different topologies for current sourcing and sinking. Also, you can easily adjust the value of the current reference by simply adjusting the circuit's input voltage....

Ask the Applications Engineer (V/F Converters): AN-361 Analog Devices Application Notes (app note added 2/06)

AN-C: V/F Converter ICs Handle Frequency-To-Voltage Needs: National Semiconductor Application Note (app note added 2/06)

AN967: Bidirectional VF Control of Single and 3-Phase Induction Motors using the PIC16F72: Microchip Application Note Published 27-Jan-05 (app note added 6/06)

AN-361: Ask the Applications Engineer (V/F Converters): AN-361 Analog Devices Application Notes (app note added 2/06)

AN-277: Applications for the AD537 Voltage to Frequency Converter: AN-277 Analog Devices Application Notes (app note added 2/06)

Acceleration to Frequency Circuits: AN-411 Analog Devices Application Notes (app note added 2/06)

10 Khz VF0.02% V/F Converter Consumes Only 26 µA: 07/04/96 EDN-Design Ideas / (added 11/05)

C uses Charge Pump Variation: 04/09/98 EDN-Design Ideas / (added 3/03)

AN-C: V/F Converter ICs Handle Frequency-To-Voltage Needs: National Semiconductor Application Note (app note added 2/06)

Using the ADT7461 as a Multichannel Temperature Sensor: AN-702 Analog Devices Application Note (app note added 2/06)

Temperature-Based Fan Control using the MAXQ2000 Microcontroller: App Note 3620: Maxim IC (application note added6/06)

Thermofan to Keep Your Amp Cool: (circuit / schematic design added 6/06)

TC64X/TC64XB Demo Board for Fan Speed Controllers: Fan control module allows the user to quickly prototype fan control circuits based on the TC642 or TC646 PWM Fan Control IC's. Its uses though hole components for easy user assembly and evaluation. (app note added 6/06)

Suppressing Acoustic Noise in PWM Fan Speed Control Systems: Microchip Application Note Published 27-Jul-04 (app note added 2/06)

Speed Error in PWM Fan Control Systems (TC646, TC647, TC649): Microchip Application Note Published 27-Jul-04 (app note added 2/06)

MOSFET Switch Provides Efficient AC/DC Conversion: 02/17/00 EDN-Design Ideas / (schematic / circuit added 11/03)

Fan Speed Control is Cool!: App Note 1784: Maxim IC (application note added6/06)

Fan timer Based on Motorola 68HC908QT2: (circuit / schematic design added 6/06)

Computer Fan Speed Tacho Out Circuit: Add a Fan Speed Monitor Lead to Any 12V Two Wire Fan: You will find this identical circuit inside most 3 wire computer fans with speed monitoring output to the motherboard. 
Peel off the sticker from the fan hub in order to access a motor winding pin for connecting up the tacho circuit. (added 2/05)

Circuit Generates Analog FAN-Speed Control: App Note 1125: Maxim IC (application note added6/06)

AN764: Implementing Temperature-Based Variable Fan Speed Control in Nlx Power Supplies: Microchip Application Note Published 4-Feb-03 (app note added 2/06)

AN-612: ADT7463 Configurations: AN-612 Analog Devices Application Note (app note added 2/06)

AN-699: Noise Filtering and the ADT7461: AN-699 Analog Devices Application Note (app note added 2/06)

AC line powers microcontroller-based fan-speed regulator: 11/9/2006 EDN Design Ideas / (added 02/07) Capacitor drops voltage, decreases waste heat in line-powered controllers.

AN-1262: Four-Speed Fan Control using Simple Remote Diode Temperature Sensor: National Semiconductor Application Note (app note added 2/06)

AN-1262: Four-Speed Fan Control using Simple Remote Diode Temperature Sensor: National Semiconductor Application Note (app note added 2/06)

1 Second Time Base from Crystal Oscillator: (electronic circuit added 05/07)

2 Transistor Atomic Frequency Standard: (schematic added 8/03)

2.8 GHz prescaler keeps cost down: 07)/20/00 EDN-Design Ideas / (added11/05)

28 LED Clock Timer 72 LED Clock: programmable clock Timer circuit that uses individual LEDs to indicate hours and minutes (added 4/02)

40 LED Bicycle Light (555 Timer 6 Volt): (schematic added 8/03)

555 DC-AC Inverter: (circuit / schematic design added 6/06)

555 Go/No Go Tester: (schematic added 8/03)

555 Makes Handy Voltage to time Converter: 02/01/01 EDN-Design Ideas / (added 06/03) The circuit in Figure 1 is a simple, low-cost voltage-to-time converter using ubiquitous 555 timer chip. You can use IC's monostable multivibrator as a voltage-to-time converter by connecting analog-voltage input to charging resistor, R, instead of connecting R to VCC. With this modification,....

AN-1173: High Speed BUS LVDS Clock DistributionUsing the DS92CK16 Clock Distribution Device: National Semiconductor Application Note (app note added 2/06)

AN-349: Keys to Longer Life for CMOS: AN-349 Analog Devices Application Notes (app note added 2/06) Here's How CMOS Can be Protected Against Abuse

AN-214: Ground Rules for High Speed Circuits: AN-214 Analog Devices Application Notes (app note added 2/06) Layout and Wiring Are Critical in Video Converter Circuits.

Ad-03: Effects of Aperture Time and Jitter in a Sampled Data: National Semiconductor Application Note (app note added 6/06)

9 Second Digital Readout Timer: (circuit added 7/02)

9 Second LED Relay Timer: (circuit added 7/02)

Acquisition Times of the ADN2812: AN-757 Analog Devices Application Notes (app note added 6/06)

74ACT74 makes Low-skew clock divider: 12/17/98 EDN-Design Ideas / (added 11/05) Serial-data systems often generate an internal clock at twice data rate for mid-bit sampling or for generating bi-phase codes. External equipment and some internal processes require a clock that runs at data rate. Simply dividing twice-rate clock with a flip-flop generates a data-rate clock that is ....

Cheap Crystal filter: Ladder filter using six 4.43MHz Crystals. Building cheap side band filter for your bome brew SSB Rig. . (Circuit added 9/04)



1 Second Time Base from Crystal Oscillator: (Electronic circuit added 7/03)

AN-213: Low Cost, Two-Chip, Voltage-Controlled Amplifier and Video Switch: AN-213 Analog Devices Application Notes (app note added 2/06)

8 Hints for Making Better RF Counter Measurements: Agilent Application Note (Circuit / schematic design added 6/06)

Simplified Analysis of Phase-Locked Loop Capture and Tracking Range (AN 1200-7): Agilent Application Note (Circuit / schematic design added 6/06)

Microcontroller Makes Effective Frequency Counter: 11/23/00 EDN-Design Ideas / (Circuit / schematic design added 6/06)

Transition Counter Gauges Thermal Stability: 01/04/96 EDN-Design Ideas / (Schematic / circuit added 10/05)

Amplifiers Perform Precision Divide by 2 Circuit: 02/06/03 EDN Design Ideas / (added 1/05) The classic implementation of a voltage-halving circuit uses two equal-value resistors. Using 1% resistors provides a divider output with 2% accuracy. For most applications, this performance is cost-effective and more than adequate. However, when you need extreme precision, this approach requires correspondingly accurate resistors and can become expensive....

Cheap 40kHz Clock: (circuit / schematic design added 6/06)

Clock Divider Circuit: (circuit / schematic design added 6/06)

Counter Provides Divide by 45 Function: 05/22/97 EDN-Design Ideas / (added 3/03)

Avoiding Passive-Component Pitfalls: AN-348 Analog Devices Application Notes (app note added 2/06) The Wrong Passive Component Can Derail Even Best Op Amp or Data Converter. Here Are Some Basic Traps to Watch For.

Applications of the LM392 Comparator Opamp Ic: National Semiconductor Application Note 04-Nov-1995 (app note added 4/02)

AN-87: Comparing the High Speed Comparators: National Semiconductor Application Note (app note added 2/06)

AN-41: Precision IC Comparator Runs from +5V Logic Supply: National Semiconductor Application Note (app note added 2/06)

AN-348: Avoiding Passive-Component Pitfalls: AN-348 Analog Devices Application Notes (app note added 2/06) The Wrong Passive Component Can Derail Even Best Op Amp or Data Converter. Here Are Some Basic Traps to Watch For.

An IC Voltage Comparator for High Impedance Circuitry: National Semiconductor Application Note (app note added 2/06)

Absolute Value Circuit Delivers High Bandwidth: 05/15/03 EDN Design Ideas / (added 1/05) Most absolute-value circuits have limited bandwidth and high component count, and y require several matched resistors. The circuit in Figure 1 uses three fewer components than most absolute-value circuits require, and only two of resistors must have 1% tolerance to obtain 1% accuracy. This circuit's output voltage is an accurate representation of absolute value of input signal,......

25-Pin PC Serial Port to MIDI Synthesizer Interface Cable: (electronic circuit added 4/05)

9 to 9 Pin (Female) Null Modem Cable: (circuit / schematic design added 6/06)

9-pin null modem cable: (circuit / schematic design added 6/06)

A Serial Infrared Remote Controller: (electronic circuit added 4/05)

AN-916: A Practical Guide to Cable Selection: National Semiconductor Application Note (app note added 2/06)

Apple Mac to MIDI Synthesizer Interface Cable: (electronic circuit added 4/05)

Casio QV-200 Digital Camera Cable. : Lose your cable? Build it yourself and save $29. Fits many QV models. (added 7/03)

Commonly Used RS-232 Serial Port Cables: (design circuit added 8/02)

Interface Cable for Casio Qv-200 Digital Camera: (electronic circuit added 4/05)

Laptop Computer Serial Port Power Booster: (schematic / circuit design added 9/02)

8k and 16k Microwire EEPROM Enhancements: Microchip Application Note Published 11-Feb-04 (app note added 2/06)

7 Segment Rolling Display using PC: It is very interesting and convenient to be able to control everything while sitting at your PC terminal. Here, a simple hardware circuit and software is used to interface a 7-segment based rolling display. The printer port of a PC provides a set of points with some acting as input lines and some ors as output lines. Some lines are open collector type which can be used as input lines. The circuit given here can be used for interfacing with any type of PC’s printer port. The 25-pin parallel port connector at back of a PC is a combination of three ports.. (added 10/05)

300 Baud Modem Circuit Schematic: Text is in French (added 4/05)

2m 20m Transverter: (circuit / schematic design added 6/06)

24 Line Parallel Interface for the PC : (electronic circuit added 7/03)

200 Watt Modified PC Power Supply 13.5 Volt 14 Amp: (electronic circuit added 4/05)

25 Watt MOSFET Amplifier: High Quality simple unit. No need for a Preamplifier (added 9/04)

25-Pin PC Serial Port to MIDI Synthesizer Interface Cable: (electronic circuit added 4/05)

2 Channel Port Powered RS-232 to RS422 Converter: information on commercial product, datasheet includes full circuit diagram (added 4/02)

2 Transistor Circuit Replaces IC #1: 02/07)/02 EDN-Design Ideas / (added 4/02) -Jim Hagerman's article Linear Technologies recently introduced LTC4300 chip buffers I2C clock and data lines to and from a hot-swappable card. This task is difficult because IC must work bidirectionally.

2 Transistor Circuit Replaces IC: Linear Technology's recently introduced LTC4300 chip buffers I2C clock and data lines to and from a hot-swappable card. This task is difficult because IC must work bidirectionally (added 08/05)

(AN-2) Ultra2 SCSI White Paper: Application Note Microsemi 1202 (added 2/07)

Salt Water Battery: (Circuit / schematic design added 6/06)

Variable Voltage Source: The high current regulator below uses an additional winding or a separate transformer to supply power for the LM317 regulator so that the pass transistors can operate closer to saturation and improve efficiency. For good efficiency the voltage at the collectors of the two parallel 2N3055 pass transistors should be close to the output voltage. The LM317 requires a couple extra volts on the input side, plus the emitter/base drop of the 3055s, plus whatever is lost across the (0.1 ohm) equalizing resistors (1volt at 10 amps), so a separate transformer and rectifier/filter circuit is used that is a few volts higher than the output voltage..... (added 4/05)

Signal Sources Conditioners and Power Circuitry: AN98 Linear Technology Eighteen circuits are presented in this compilation. Signal sources include a voltage controlled current source, an amplitude/frequency stabilized sine wave oscillator, a versatile, 0V to 50V wideband level shift and four sub-nanosecond pulse generators with risetimes as low as 20ps. Five signal conditioners appear; a unique, .... (added 9/06)

High Voltage Linear Regulator and Constant Current: Supertex Semiconductors (app note added 6/06)

Constant Current Battery Charger: (circuit added 7/02)

AN-D18: DN25 Series: Constant Current Sources And: Supertex Semiconductors (app note added 2/06)

AN-D16: LND1 Series: Constant Current Sources And: Supertex Semiconductors (app note added 2/06)

Build a Precise DC Floating Current Source: 08/18/05 EDN Design Ideas / (added 11/05) Use a general impedance converter and resistors to develop a specialized current source.

Circuit Simulates Contact Bounce : 05/08/97 EDN-Design Ideas / (added 2/06)

Switch Debouncer uses Only One Gate: 05/30/02 EDN Design Ideas / (schematic / circuit added 11/03) The circuit in Figure 1 produces a single debounced pulse each time you press S1. Moreover, the circuit uses only logic power from the remote pull-up resistor, R2. You can use the circuit to detect when a key is pressed in a nonenergized device, such as a device in a system that's just coming up from standby

Pushbutton Switch Debouncer: (electronic Circuit diagram added 03/03)

µC acts as dedicated motor control : 09/11/98 EDN-Design Ideas / (added 6/06)

µC Provides Wireless Keypad Control: 10/08/98 EDN-Design Ideas / (added 6/06) Portable systems, such as telephone handsets, make extensive use of low-dropout (LDO) regulators. se components provide noise-sensitive parts with a stable power-supply line. ....

12 Volt Strobe Circuit: this circuit uses12V DC instead od mains AC. This is very good idea if you don't want to mess with direct mains voltage connected circuit or you want to run stroboscope from batteries. (added 4/02)

2 Wire Remote Microphone Amplifier : (electronic circuit added 7/03)

230 Volt AC Motor Controller: controls speed of230-Volt AC universal motor, in PDF format, text in Finnish (added 6/06)

2-wire Lamp Flasher: This circuit has been designed to provide that continuous light lamps already wired into a circuit, become flashing. Simply insert circuit between existing lamp and negative supply. Especially suited for car or panel pilot lights, this device can drive lamps up to 10W.... (design added 11/06)

35kHz Magnetic-Radiation Remote-Control: (electronic circuit added 4/05)

80C31 Stepper Motor Controller: (electronic circuit added 4/05)

12 Volt DC to 120 Volt AC Inverter: this inverter should solve that problem. It takes12 VDC and steps it up to120 VAC. -Wattage depends on which transistors you use for Q1 and Q2, as well as how "big" a transformer you use for T1. inverter can be constructed to supply anywhere from1 to1000 (1 KW)-Watts. (added 4/02)

AN17 Emergency Lighting Systems and Battery Powered Fluorescent Lighting: High Current To92 Switching Transistors Provide 87% DC-AC Conversion Efficiency: Zetec Semiconductors Applications Notes An overview of principles behind typical emergency lighting systems, fluorescent tube behaviour, and requirements of transistors for efficient voltage inversion. The note also includes two "Royer" based designs for low voltage systems. (app note added 6/06)

AN-327: DAC ICs: How Many Bits Is Enough?: AN-327 Analog Devices Application Notes (app note added 6/06) Digital audio playback DACs are available in a variety of different architectures--each with it's own performance tradeoffs.

Choosing DACs for Direct Digital Synthesis: AN-237 Analog Devices Application Notes (app note added 6/06)

DC/AC Inverter (interq): (electronic circuit added 4/05)

DC/AC Inverter (interq): (electronic circuit added 4/05)

Emergency Lighting Systems and Battery Powered Fluorescent Lighting: High Current To92 Switching Transistors Provide 87% DC-AC Conversion Efficiency: Zetec Semiconductors Applications Notes An overview of the principles behind typical emergency lighting systems, fluorescent tube behaviour, and the requirements of the transistors for efficient voltage inversion. The note also includes two "Royer" based designs for low voltage systems. (app note added 6/06)

60V 3A Step-Down DC/DC Converter has Low Dropout and 100µA Quiescent Current: DN352 - Design Notes (Linear Technology) (app note added 6/06)

Passive Differentiator tops Active Designs: 04/28/94 EDN-Design Ideas / (Electronic Circuit diagram added 03/03) The simple, passive differentiator in Fig 1 achieves accurate differentiation even at frequencies approaching the limit, fO=1/(2[pi]RC). The circuit surpasses the performance of an op-amp-based differentiator. The trick is to add a carefully selected inductor, [phi], to eliminate the first- and second-order terms in the equation for the phase angle, f, between the input and output signals. Ideally, of course, to achieve perfect differentiation, this phase angle should be equal....



µC controls digital potentiometer : 10/08/98 EDN-Design Ideas / (added 11/05)

10 Tricks for Interfacing to the PIC16c508: (electronic circuit added 7/03)

15-Step Digital Power Supply: (electronic Circuit / Schematic added 10/04)

32 Bit Serial Receiver (57.6 K Baud TTL and CMOS): (electronic schematic / circuit added 11/05)

51 MHz Frequency Counter Voltage Meter and SwR/PWR Indicator: (electronic Circuit diagram added 02/07)

68HC11 Instruction Halts External RC Clock: 04/27/95 EDN-Design Ideas / (added 3/03)

8 Hints for Debugging Microcontroller Based Design: Agilent Application Note (app note added 6/06)

8 Hints for Debugging Siemens MCU-based Designs: Agilent Application Note (added 6/06)

8051 Development System Circuit Board #2: (electronic circuit added 4/05)

9 Second Digital Readout Timer: (circuit / schematic design added 6/06)

µP Displays 10 Bit Data on Three LEDs: 11/07/96 EDN-Design Ideas / (added 08/05) circuit in Figure 1 uses a PIC16C55 µP to read 10-bit binary data and directly display data in decimal format on three common-cathode LED displays. If value of data exceeds 999, displays show three hyphens (---) to represent overflow. PIC16C55 has high drive capability. Each output pin can source 20 mA and sink 25 mA; outputs can thus directly drive LED display

9 Second Digital Readout Countdown Timer: This circuit provides a visual 9 second delay using a 7 segment digital readout LED. When the switch is closed, the CD4010 up/down counter is preset to 9 and the 555 timer is disabled with the output.... (added 3/07)

9 Second Digital Readout Timer: (circuit added 7/02)

Animated LED Signboard (PIC16C84): (electronic circuit added 4/05)

Connecting AT90S2313 with LCD Display 2x16 Char and 4x4 Keypad: (electronic circuit added 4/05)

Interfacing 16x2 Character LCD to Parallel Port: (circuit added 7/02)

µC implements Pushbutton Light Dimmers: 06/18/98 EDN-Design Ideas / (added 08/05) A project required building a synchronous-demodulator circuit to track a line drawn on paper. beauty of synchronous-modulator/demodulator approach is its inherent noise rejection. method rejects nearly all out-of-band noise, wher from internal drift or external illumination. This rejection is a boon in optical tracking, where return signal is inevitably buried in 120-Hz ambient light, amplifier offsets, and temperature drifts. circuit in Figure 1 is inexpensive, and it operates from 5V dc. circuit scans eight LED/sensor pairs every 22 msec and stores result in eight sample/hold (S/H) capacitors for interrogation by a µP-driven ADC. purpose of circuit is to determine which sensor is above line.

Circuit optimizes PhotoTransistor Bandwidth : 04/09/98 EDN-Design Ideas / (added 3/03)

Control Interface for Standard 0 - 10VDC Dimmers / ABR-42021: Fairchild Application Notes / (app note added 6/06)

A Ballast that can Be Dimmed from a Domestic (Phase Cut) Dimmer.: A system has now been developed, based around IR2156, where ballast is able to operate with minimal flicker over a considerable portion of adjustment range of a dimmer and light output may be controlled over this range from maximum output down to around 10%. (added 6/06)

4 Channel dimmer rack: (electronic circuit added 4/05)

8 Bit Digital Light Intensity Controller : (design circuit added 8/02)

A GPS Receiver Based Frequency Standard: (electronic circuit added 4/05)

Aisin-Seiki GPS-Receiver (Us$20 GPS): (electronic circuit added 4/05)

Alternative Power Source for Magellan GPS Receivers: (electronic circuit added 4/05)

Digital Compass Schematic: (electronic circuit added 7/03)

GPS Handheld: Intersil Application Block Diagram (app note added 6/06)

GPS Receiver Support Kit: (electronic circuit added 4/05)

Inertial Navigation System uses Silicon Sensors: 09/16/04 EDN Design Ideas / (added 1/05) A strap-down inertial-navigation system uses silicon sensors to measure displacement without entailing the bulk and expense of moving parts or GPS receivers. For example, a three-axis accelerometer and three angular-rate sensors can determine the position and velocity of a vehicle such as a robot or radio-controlled aircraft....

U-Blox GPS receiver Board: (electronic circuit added 4/05)

Ultra Low Noise Precision High Speed Op Amps: Linear Technology LT1028(app note added 02/05)

16x16 LED Matrix and Driver: (circuit added 9/04)

2 Wire LCD Interface using PIC16cf84: (schematic / circuit design added 9/02)

20 Db Amplifier and High Current Balanced Line Driver: (circuit added 7/02)

A Design and Manufacturing Guide for the Lead Frame Chip Scale Package (LFCSP): AN-772 Analog Devices Application Notes (app note added 6/06)

7 Segment Rolling Display using PC: It is very interesting and convenient to be able to control everything while sitting at your PC terminal. Here, a simple hardware circuit and software is used to interface a 7-segment based rolling display. The printer port of a PC provides a set of points with some acting as input lines and some ors as output lines. Some lines are open collector type which can be used as input lines. The circuit given here can be used for interfacing with any type of PC’s printer port. The 25-pin parallel port connector at back of a PC is a combination of three ports.. (added 10/05)

72 LED Clock: (circuit added 7/02)

Digital Step Km Counter Max.: Pedometer has a range of 9.950 meters with2-digits. Slip it in pants pocket for walking and jogging (Electronic circuit design added 02/05)



Pedometer: Pedometer has a range of 9.950 meters with2-digits. Slip it in pants pocket for walking and jogging (Electronic circuit design added 02/05)

Unusual Frequency Dividers: (electronic circuit added 7/03)

66000 Modular Power System: Agilent Application Note (app note added 6/06)

9-V Stabilized Power Supply: (added 2/06)

6 to 12 Volt Converter: This circuit can provide up to 800mA of12V power from a 6V supply. The circuit is simple, about 75% efficient and quite useful. (added 4/02)

5 to 1.8V converter works without magnetics: 04/13/00 EDN-Design Ideas / (added 11/05)

3A Point-of-Load Power Supplies - MP1570 - DN0004: Monolithic Power Systems, Inc - Design Note - (added 6/06)

1119 Simple Regulator Provides ±12 Volt from 5 Volt Source: National Semiconductor Application Note 31 Aug2001 (app note added 7/02)

12 Volt 30 Amp Power Supply: uses a single 7812 IC voltage regulator and multiple outboard pass transistors, this power supply can deliver output load currents of up to30 amps (added 6/06)

1.3V Power Supply: This is a replacement power source for 1.3V mercury cells or other small batteries. It has many uses and I use this circuit in my computer to power a front panel multi adapter which has a digital thermometer. (added 6/06)

0 to 300 Volt Adjustable Power Supply: This is a simple circuit that can provide an adjustable voltage source of0 to330 Volts. The supply is short-circuit proof: the current is limited to about100mA. (added 6/06)

+30V DC-DC converter: introduce the compact DC-DC converter in this page. I found this converter at the junk shop. I attempted to examine the characteristic of this converter. The input voltage is +5 V, the output voltage is +30 V and can get the about 20-mA output current. The IC(CD-1846P) to be using with this converter becomes the manufacturing stop already. However, TDK said that it was the discontinuation part and I could not acquire the data. Because it may become the reference when you use the similar circuit, I introduce in the contents of the converter. (app note added 4/05)

+5 to-15 Volts DC Converter: National Semiconductor - Application Note (app note added 2/06)

Ask the Applications Engineer 1-Multi Troubles: AN-354 Analog Devices Application Notes (app note added 2/06)

AN-759: Expanding the Number of DAC Outputs on the ADUC8xx and ADUC702x Families (uC012): AN-759 Analog Devices Application Notes (app note added 2/06)

12 V DC: 120 VAC Inverter Schematic: An Inverter is a device that converts 12 volts DC to 120 volts AC. , which is what we use in our homes. This project will handle about 300 watts, which is perfect for lights, small TV's and radio equipment. This Inverter takes 12 volt DC and steps it up to 120 volt AC. wattage depends on which transistors you use for Q1 and Q2, as well as "Amp Rating" of transformer you use for T1. This inverter can be constructed to supply anywhere from 1 to 1000 (1 KW) watts. If Q1, Q2 are 2N3055 NPN Transistors and T1 is a 15 A transformer, n inverter will supply about 300 watts. Larger transformers and more powerful transistors can be substituted for T1, Q1 and Q2 for more power. Note: Don't try to run inductive loads (motors...) off this inverter. (added 4/05)





Two Tone Generator: This two-tone generator includes 3 ICs NE555 Astable Multivibrators. You can vary the duration of each tone by changing the 10k resistor or 100MF capacitor at IC1 or changing resistors and capacitors at IC1/2 for higher or lower tone. (added 6/03)

Simple Fix Adds Door-Chime Repeater: 05/13/99 EDN-Design Ideas / (added 11/05)

Automotive Relay Drivers using the Zvn4206av: Protection Free Interfacing with Avalanche Rated MOSFETs: Zetec Semiconductors Applications Notes An alternative solution is provided to usual large package Darlington effected relay driver. The ZVN4206AV has been designed, processed and rated to withstand significant energy within breakdown region. This allows part .... (app note added 2/06)

AT89C2051 Serial Coms to LED Driver: (circuit / schematic design added 6/06)

AT89C2051/4051 Driving Dot Led: (circuit / schematic design added 6/06)

AN-H20: HVCMOS Drivers for Non-Impact Printing: Supertex Semiconductors (app note added 6/06)

AN-H44: HV832 Dual EL Lamp Driver Circuits: Supertex Semiconductors (app note added 6/06)

(AN 30) LX1995 LED Driver: Camera Flash Application: Application Note Microsemi 1313 (added 2/07)

(AN-13) LX1686 Backlight CCFL Direct Drive Design Reference: Application Note Microsemi 1401 (added 2/07)

0 to 24 DB Gain Amplifier and Balanced Line Driver : (electronic schematic / circuit added 4/02)

12 Volt DC Fluorescent Lamp Driver: This fluorescent lamp driver uses a normal 120 to 6V step-down transformer in reverse to step12V to about350-Volt to drive a lamp without need to warm filaments. (added 6/06)

128x64 LCD Driver for AT90S2313 (Zip File) : (electronic circuit added 4/05)

16x16 LED Matrix and Driver: (circuit / schematic design added 6/06)

1a Flash LED Driver : Sipex Application Note (app note added 6/06)

20 DB Amplifier and High Current Balanced Line Driver : (circuit added 7/02)

Advanced IGBT Driver Application Manual: Application Note Microsemi 1903

AN-521: Dual Tone Multiple Frequency (DTMF): National Semiconductor Application Note (app note added 2/06)

AN-666: DTMF Generation with 3.58 MHz Crystal: National Semiconductor Application Note (app note added 2/06)

DTMF Decoder for PC: Displays DTMF digits on your computer screen in real-time. (circuit added 8/06)

Radio Remote Control using DTMF #2: Here is a circuit of a remote control unit which makes use of the radio frequency signals to control various electrical appliances. This remote control unit has 4 channels which can be easily extended to 12. This circuit differs from similar circuits in view of its simplicity and a totally different concept of generating the control signals..... (added 09/05)

Simple 4-CH Remote Control: 4 channel remote control using MC145026, MC145027. (circuit added 8/06)

Radio Remote Control using DTMF: (electronic circuit added 10/05)

Synthesize Optimal Digital-Frequency Dividers: 05/13/99 EDN-Design Ideas / (added 11/05)

Precision Divide by Two Analog Attenuator Needs No External Components: 03/17/05 EDN Design Ideas / (added 11/05) Many modern A/D converters offer only a 5V input range, and using these converters with a 65V or larger input signal gives the designer a problem: how to discard half of a good analog signal without introducing errors and distortion. To solve the problem, you can use an attenuator comprising two operational amplifiers and two resistors (Figure 1).

Clock Divider: (Circuit / schematic design added 6/06)

Charge Pump Doubles Negative Voltage: Maxim Application Note #782 (Circuit / schematic design added 6/06)

Frequency Divider Adapts to I / O Conditions: 09/29/94 EDN-Design Ideas / (Electronic Circuit diagram added 03/03) CanadaThe circuit in Figure 1 accepts an input clock signal, such as from a crystal oscillator, and divides the frequency according to the input divisor word. You can easily modify the basicdesign of this versatile PLD-based ...

Make a simple PC based frequency meter: 04/29/99 EDN-Design Ideas / (added 11/05) A simple, low cost, and precision frequency meter uses only two pins of a pc parallel port (Figure 1). The TTL-level periodic input signal with frequency fIN connects to the ACK pin of LPT1. This input produces an IRQ7 hardware in- terrupt on every rising edge (Figure 2). The software counts the number of IRQ7 interrupts in the time unit of timebase T. If this timebase is 1 sec, the frequency of the input signal equals the number of IRQ7 interrupts in 1 sec....

Single Supply Operation of JFET Multiplexers: AN-32 - Analog Devices Application Notes (added 2/06)

Avoiding Passive-Component Pitfalls: AN-348 - Analog Devices Application Note (added 2/06) The Wrong Passive Component Can Derail Even the Best Op Amp or Data Converter. Here Are Some Basic Traps to Watch For.

AN-769: Generating Multiple Clock Outputs from the AD9540: AN-769 - Analog Devices Application Notes (added 2/06)

AN-35: Understanding Crosstalk in Analog Multiplexers: AN-35 - Analog Devices Application Notes (Circuit / schematic design added 6/06)

AN-345: Grounding for Low-and-High-Frequency Circuits: AN-345 - Analog Devices Application Note (Circuit / schematic design added 6/06) Know Your Ground and Signal Paths for Effective Designs. Current Flow Seeks Path of Least Impedance-Not Just Resistance....

µC Based Circuit Performs Frequency Multiplication: 05/27/99 EDN-Design Ideas / (Circuit / schematic design added 6/06)

AN-249: over Voltage Protection for the ADG5XXA Multiplexer Series: AN-249 - Analog Devices Application Notes (Circuit / schematic design added 6/06)

Circuit makes simple FSK modulator: 10/11/2001 EDN - Design Ideas / (added 11/03) The need for a compact telemetry system poses a challenge for designing a small, light, low-component-count system. Interfacing serial data from the microprocessor is also difficult because most low-cost RF transmitters do not accept dc levels at the input. Commercial FSK (frequency-shift-keying) modulators are bulky and need many passive components. .

Low Cost Programmable Oscillator Operates at 2 GHz: 05/11/00 EDN-Design Ideas / (added 7/03) All wireless communication systems need a local oscillator. Figure 1 shows a low-cost PLL circuit for the 2-GHz band for such applications as industrial, scientific, and medical (ISM) and satellite personal-communication systems (S-PCS). The central...

Voltage-To-Frequency/Frequency-To-Voltage Converter: Microchip Application Note - Published 12-Nov-02 (added 2/06)

Precision Voltage-To-Frequency Converter: AN-C: Application Note CV/F Converter ICs Handle Frequency-to-Voltage Needs, 3-Oct-02 (added 2/06)

New Phase Locked Loops: (Electronic Schematic / circuit added 4/02)

F/V Converter has High Accuracy: 05/12/94 EDN Design Ideas / (added 2/06)

Frequency-to-Voltage Converter uses Sample-and-Hold to Improve Response and Ripple: National Semiconductor - Application Note (Circuit / schematic design added 6/06)

Circuit Converts Pulse Width to Voltage #2: 10/28/99 EDN-Design Ideas / (Electronic Schematic / circuit added 4/02) -- The circuit is optimized for a positive-going pulse width of1 to2 msec, repeating at intervals of approximately17 msec. The output produces a voltage of0.95V for a1-msec pulse to2.25V for a2-msec pulse.

Function Generator #2: (electronic (schematic / circuit added 11/05)

Function Generator #4: (schematic / circuit design added 9/02)

Function Generator #5: Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc. (app note added 6/06)

Improve Function Generators with Matched D/A Converters: AN-322 Analog Devices Application Notes (app note added 6/06) AD7528 Dual 8-Bit CMOS Multiplying DAC Makes Function Generation Practical and Affordable

Using a Function/Arbitrary Waveform Generator to Generate Pulses: Agilent Application Note (added 6/06)

MAX038 Function Generator: This is a function generator that can generates 10Hz through 20MHz in six ranges. Analog output can select one of any wave forms, sine, triangle or square. TTL output can select 50% fixed duty or variable pulse width. (added 6/06)

LM2907 Tachometer/Speed Switch Building Block Applications: National Semiconductor Application Note 04-Nov-1995 (circuit added 7/02)

AN-205: Video Formats and Required Load Terminations: AN-205 Analog Devices App Notes (app note added 2/06)

Adding HART® Capability to the AD421, Loop-Powered 4 mA–20 mA DAC using the 20C15 HART Modem: AN-534 Analog Devices Application Notes (app note added 2/06)

A Digitally Programmable Gain and Attenuation Amplifier Design: AN-137 Analog Devices Application Notes (app note added 2/06)

12-Bit Voltage-Output DACs for Single-Supply 5V and 12V Systems: AN-225 Analog Devices Application Notes (app note added 2/06)

µC RePrograms Audio DAC via Serial Interface: 01/07/99 EDN-Design Ideas / (added 08/05) [Note: File contains multiple circuits scroll to find this circuit] You can use a simple µC to continuously program an audio DAC so that it operates in a 20-bit resolution mode ( Figure 1 ). After power-on, PCM1710 delta-sigma DAC (Burr-Brown Corp, www.burr-brown.com) operates in its default 16-bit resolution....

Voltage-To-Frequency/Frequency-To-Voltage Converter: Microchip Application Note Published 12-Nov-02 (app note added 2/06)

Two Diode Odd Order Multiplier: (electronic circuit added 7/03)

New Phase Locked Loops: (electronic (schematic / circuit added 4/02)

Hear Amateurs on Your FM Radio!: (electronic (schematic / circuit added 2/05)

Frequency Tripler using the Ca3028: (electronic circuit added 7/03)

Frequency Doubler Operates on Triangle Waves: 03/14/96 EDN-Design Ideas / (added 03/03)

Delay Line implements Clock Doubler: 07/18/96 EDN-Design Ideas / (added 3/03)

Circuit Converts Pulse Width to Voltage #2: 10/28/99 EDN-Design Ideas / (added 4/02) -The circuit is optimized for a positive-going pulse width of1 to2 msec, repeating at intervals of approximately17 msec. The output produces a voltage of0.95V for a1-msec pulse to2.25V for a2-msec pulse.

900MHz Down Converter Consumes Little Power: 06/22/95 EDN-Design Ideas / (added 3/03)

555 Makes Handy Voltage to time Converter: 02/01/01 EDN-Design Ideas / (added 11/05) The circuit in Figure 1 is a simple, low-cost voltage-to-time converter using ubiquitous 555 timer chip. You can use IC's monostable multivibrator as a voltage-to-time converter by connecting analog-voltage input to charging resistor, R, instead of connecting R to VCC. With this modification,....

AN-279: Using the AD650 Voltage-to-Frequency Converter as a Frequency-to-Voltage Converter: AN-279 - Analog Devices Application Notes (Circuit / schematic design added 6/06)

Circuit Converts Pulse Width to Voltage: 10/25/01 EDN Design Ideas / (added 1/05) The circuit in Figure 1 converts pulse information to a clean dc voltage by the end of a single incoming pulse. In another technique, an RC filter can convert a PWM signal to an averaged dc voltage, but this method is slow in responding. Converting low-duty-cycle pulse information is slower yet. ...

LM2907 Tachometer/Speed Switch Building Block Applications: National Semiconductor Application Note 04-Nov-1995 (circuit added 7/02)

Using the AD650 Voltage-to-Frequency Converter as a Frequency-to-Voltage Converter: AN-279 - Analog Devices Application Notes (Circuit / schematic design added 6/06)

Voltage-To-Frequency/Frequency-To-Voltage Converter: Microchip Application Note - Published 12-Nov-02 (added 2/06)

Converter ignores Power Supply Variations: 01/05/95 EDN-Design Ideas / (Electronic circuit design added 02/05)

Circuit Converts Pulse Width to Voltage #2: 10/28/99 EDN-Design Ideas / (added 1/04) -- PDF contains multiple circuits - scroll to find this circuit. --- The circuit is optimized for a positive-going pulse width of1 to2 msec, repeating at intervals of approximately17 msec. The output produces a voltage of0.95V for a1-msec pulse to2.25V for a2-msec pulse.

42 Mc Band to 88 Mc Band (Retrofit Converters): (Electronic circuit added 7/03)

RF Frequency Linear Tuning Varactors: MicroNote 705 from Microsem (Circuit / schematic design added 6/06)

CMOS inverters convert RF to digital signal: 1/5/06 EDN Design Ideas / (added 10/06) Hex-inverter-based design suits frequencies up to180 MHz.

50 MHz to 146 MHz Converter: (added 2/05)

Zero Crossing Detector: Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc. (Circuit / schematic design added 6/06)



Time tag impulses with zero crossing circuit: 01/24/2002 EDN - Design Ideas / (added 11/03) A "constant-fraction discriminator" usually performs the time-tagging of impulsive events, which have a peaking time of the signal amplitude. The implementation of this technique requires a delay in the input signal of approximately the same amount as the signal's rise time. You can attain this delay by using a coaxial cable of an appropriate length.



Self Powered Sine to Square Wave Converter: Converts sine to square waves without a power-source Useful as a test instrument for audio purposes (Circuit added 9/04)



Voltage Controlled Oscillator ( VCO ): The oscillation frequency of the voltage controlled oscillator is controlled by the output of the PLL synthesizer and does the stable oscillation of 119.3 MHz. (Electronic circuit design added 02/05)

Pellistors: Pellistors employ catalytic combustion to measure combustible gases or vapors in air up to the Lower Explosive Limit (LEL)* of the gas. The standard sensor consists of a matched pair of elements, typically referred to as a detector and compensator (reference element). The detector comprises a platinum wire coil embedded within a bead of catalytic material. The compensator is similar except that the bead does not contain catalytic material and as a consequence is inert.(Electronic circuit design added 02/05)



MOSFET Current Mode Resonant Coil Driver: The schematic was made long after the circuit was built and perfected. Sorry. That means I cannot guarantee that it is free of errors. However, the schematic was compared to the original as best as I oould. ERRATTA: 1. The resistor network at pins 6 and 7 of the LM555 is incorrect. Instead of a fixed 200k and a 500k pot in parallel, it should be the 200k fixed in parallel with a 500k pot and the resulting two in series with a 1k fixed. Thus the 200k fixed established the maximum duty cycle, and the 1k pot establishes the minimum duty cycle. You could try eliminating the 1K, but you might damage the LM555. (Electronic circuit design added 02/05)



AN996: Designing a Digital Compass using the PIC18f2520: Microchip Application Note Published 8-Aug-05 (app note added 2/06)

Digital Compass Schematic: (circuit added 9/04)

Dinsmore 1490 Digital Compass: (electronic circuit added 4/05)

Electronic Compass Controller: Eventually we all want to know just where our robot is, so we can choose an absolute direction. Usually this type of device is quite expensive. However to our rescue comes.... (added 3/07)

Ultra Low Noise Precision High Speed Op Amps: Linear Technology LT1028(app note added 02/05)

AN728: Remote Keyless Entry and Convenience Center Reference Design with LIN Bus Interface: Microchip Application Note Published 26-Sep-02 (app note added 2/06)

Combination Lock (PIC16F84): (electronic diagram added 6/03)

Combination Lock for Car Liftgate: (circuit / schematic design added 6/06)

Electronic Combination Lock with AVR: (electronic schematic / circuit added 2/05)

Electronic Card Lock System: (electronic Circuit / Schematic added 10/04)

Digital Electronic Lock: (electronic schematic / circuit added 11/05)

Single Button Lock Provides High Security: 03/04/99 EDN-Design Ideas / (added 5/03) Figure 1 is the block diagram of an easily programmed, single-button combination lock. You operate the lock by using a series of short and long pulses from a momentary switch that masquerades as a doorbell button. The circuit uses inexpensive CMOS logic. The retriggerable timer, T1, locks out entries made after the T1 code-entry window, thereby greatly enhancing security. The circuit in Figure 2 operates as follows: The Schmitt-trigger quad NAND gate, IC1, debounces the code-entry switch and, with the aid of simple analog circuitry, produces separate outputs for activation times of less than and more than 0.3 sec. These outputs connect to the select gate, IC5. The initial entry also sets timer T1 to enable the decoded decade counter, IC3. Each entry clocks IC3.

Simple Code Lock: (electronic Circuit / Schematic added 10/04)

Failed Power Light: turns on small low voltage lighting when mains power disappears (added 7/03)

Analog Encoding: Convert switches and sensors into DMX signals. Uses are found in Haunted houses, stage plays, med events, holiday light animations, anytime you want to control DMX compatible equipment. Fog machines and strobe lights can be independly controlled be remote switches or sensors. (added 02/05)

BA1404 Stereo Encoder: BA1404 used as only stereo encoder. (circuit added 8/06)

Digital Position Encoder Does Away withADC: 05/08/97 EDN-Design Ideas / (added 6/06)

KEELOQ® Manchester Encoding Receive Routines: Microchip Application Note Published 11-May-01 (app note added 2/06)

PIC Based Packet Radio Encoder: (circuit / schematic design added 6/06)

Remote Control Encoder/Decoder with PIC16c620 and PIC12c508: (circuit / schematic design added 6/06)

Rotary Encoder Mates with Digital Potentiometer: 02/06/03 EDN Design Ideas / (added 1/05) In developing electronic systems, designers look for products or ideas that may benefit from the better performance, smaller size, lower cost, and improved reliability that an IC can offer. Toward that end, the digital potentiometer emerged as an alternative to its mechanical counterpart, the mechanical potentiometer....

Veronica Stereo Encoder: Uses 76KHz crystal (circuit added 8/06)



F



SB-104: Fax Solution Card: National Semiconductor - Application Note (added 2/06)



Fax saver cuts wear, tear, and power: 1/8/98 EDN-Design Ideas / (added 4/'02)-- Less than $20 to cut wear and tear on your fax machine while saving power, circuit intercepts the incoming ring signal and powers up the fax machine in time to receive the fax and then turns off the fax machine after a predetermined time and awaits the next incoming fax



2 Watt Amplifier #1: (circuit / schematic design added 6/06)

2 Watt Amplifier #2: Low distortion Amplifier using discrete components (added 6/06)

2 Watt Amplifier #3: (schematic / circuit design added 9/02)

500W, Class E 27.12 MHz Amplifier Using A Single Plastic MOSFET: Application Note Microsemi-formerly Advanced Power Technology APT9903 ( app note added 2/07)

2N2222 40 Meter CW/DSB Tranceiver: (circuit / schematic design added 6/06)

AB-45 / DVD Applications: Fairchild Application Notes / (app note added 6/06)

AB-46 / DVD Applications: Fairchild Application Notes / (app note added 6/06)

AB-47 / DVD Applications: Fairchild Application Notes / (app note added 6/06)

AB-49 / DVD Applications: Fairchild Application Notes / (app note added 6/06)

A Thermoelectric Cooler Temperature Controller for Fiber Optic Lasers: AN89 Linear Technology This application note presents circuitry for maintaining 0.01°C temperature control of fiber optic lasers over wide ambient range variations. The circuitry also features high efficiency power delivery, compact size and low noise. Detailed descriptions of circuitry and results are given with special emphasis on rmal loop optimization. An appended section covers practical considerations for rmoelectric cooler-based control loops.

DVD Applications / AB-46: Fairchild Application Notes / (app note added 6/06)

DVD Applications / AB-47: Fairchild Application Notes / (app note added 6/06)

DVD Applications / AB-49: Fairchild Application Notes / (app note added 6/06)

AN677: Designing a Base Station Coil for the HCS410: Microchip Application Note Published 7-Aug-98 (app note added 2/06)

Field Strength Meter (zen 22142): (electronic circuit added 7/03)

Field Strength Meter for the137 Khz Band: (electronic circuit added 4/05)

RF field strength meter Mk1: (schematic / circuit added e/07)

RF field strength meter: (electronic circuit added 3/07)

Fire Alarm: This circuit warns the user against fire accidents. It relies on the smoke that is produced in the event of a fire. When this smoke passes between a bulb and an LDR, the amount of light falling on the LDR decreases. This causes the resistance of LDR to increase and the voltage at the base of the transistor is pulled high due to which the supply to the COB (chip-on-board) is completed. Different COBs are available in the market to generate different sounds. The choice of the COB depends on the user. The signal generated by COB is amplified by an audio amplifier. In this circuit, the audio power amplifier is wired around IC TDA 2002. The sensitivity of the circuit depends on the distance between bulb and LDR as well as setting of preset VR1. Thus by placing the bulb and the LDR at appropriate distances, one may vary preset VR1 to get optimum sensitivity. An ON/OFF switch is suggested to turn the circuit on and off as desirable. (added 8/06)

60w Ac-DC Flyback Converter: Universal AC line input Fully assembled and tested power supply with DC containing all design documentation Features: 0-4A Iout @ 15V, 87% efficiency at high line, Short Circuit protection, Over Voltage protection (added 6/06)

Design Guidelines for RCD Snubber of Flyback / AN-4147: Fairchild Application Notes / (app note added 6/06)

Design Guidelines for Off-line Flyback Converters using FPS / AN-4137: Fairchild Application Notes / (app note added 6/06)

AN-H24: Expected Voltages and Waveforms HV9120-Controlled Flyback Converter: Supertex Semiconductors (app note added 6/06)

AN-777: LM2577 Three Output, Isolated Flyback Regulator: National Semiconductor Application Note (app note added 2/06)

AN-4137 / Design Guidelines for Off-line Flyback Converters using FPS: Fairchild Application Notes / (app note added 6/06)

Fluid Level Detector #1: (added 10/02)

Fluid Level Detector #2: (Electronic Circuit / Schematic added 10/04)

Fluid Level Control Systems Utilizing the LM1830: National Semiconductor - Application Note (added 2/06)

(AN-13) LX1686 Backlight CCFL Direct Drive Design Reference: Application Note Microsemi 1401 (added 3/07)

20ma LED Ballast: I use this circuit for general use to power white LEDs, like a headset light I use on my desk and a keyboard light for my computer. I built it into a tiny Radio Shack project box (270-288), which y no longer sell. I put heat-shrink tubing around female output connector (RS P/N 273-1743), so that contacts are not exposed, but you can still plug and unplug it. Designed by Andrew R. Morris (added 6/06)

A 3-Way Dimming Cfl Ballast: The 3 way dimming system widely adopted in US with conventional filament lamps consists of a light bulb that has a modified Edison screw type base which allows 3 connections to be made to a special lamp socket that also has 3 connections. (added 3/05)

40 Watt Fluorescent Lamp Inverter: This40W fluorescent lamp inverter allows you to run40W fluorescent tubes from any12V source capable of delivering3A. (added 4/02)

AN-378: A Novel Process for Vacuum Fluorescent (VF) Display Drivers: National Semiconductor Application Note (app note added 6/06)

AN-42001 / Low Cost Non-Dimming 220V Ballast Design: Fairchild Application Notes / (app note added 6/06)

Black Light: (circuit added 7/02)

2 Transistor FM Transmitters #2: (design added 8/03)

2 Transistor LED Flasher #1: (circuit / schematic design added 6/06)

10.7MHz FM Detector: (design added 8/03)

AN-146: FM Remote Speaker System: National Semiconductor Application Note (app note added 6/06)

AN-543 - Stereo FM Transmitter (DSP, 26,085 bytes): AN-543-StereoFMTransmitter-Analog Device Application Notes (app note added 6/06)

Crystal Controlled FM Transmitter: (circuit / schematic design added 6/06)

Add a signal strength display to an FM Receiver IC: 09/05/02 EDN Design Ideas / (Electronic Circuit added 03/06) The Philips (www.semiconductors.philips.com) TDA7000 integrates a monaural FM-radio receiver from the antenna connection to the audio output. External components include one tunable LC circuit for the local oscillator, a few capacitors, two resistors, and a potentiometer to control the variable-capacitance-diode tuning....

1W portable PLL transmitter: PLL oscillator with audio limiter. (circuit added 8/06)

2 Transistor FM Transmitters: (electronic Circuit added 03/06)

400mW VCO FM transmitter: BF199, BFR91, BFR96, varicap diode BB109. (circuit added 8/06)

Crystal Controlled FM Transmitter: (electronic Circuit added 03/06)

FM Radio Transmitter: (electronic Circuit added 03/06)

FM Transmitter (rf/2bjttx): (electronic Circuit added 03/06)

FM Transmitter with Opamp: L1 is 0.112uH (this tunes to the middle of the FM band, 98 MHz, with VC1 at its centre value of 33pF). L1 is 5 turns of 22 swg enameled copper wire close-wound on a 5mm (3/16") diameter former. Alternatively, you can have a fixed 33pF cap instead of VC1 and have L1 as an adjustable molded coil (eg UF64U from Maplin). VC1 will give you a tuning range of 85 125 MHz, and a possible choice is the Philips type polypropylene film trimmer (Maplin code WL72P). Two sets of oscillator bias resistors are given, the ones in the brackets give about 20% more RF power. Mike is our favorite Omni directional sub-mini electret (Maplin code FS43W). Ant is a (lambda / 4) whip monopole (eg 76 cms of 22 swg copper wire). Q1 is configured as a Clapp oscillator. Frequency modulation results from the audio voltage changing the transistor's base-emitter capacitance. (added 3/06)

LM110-An Improved IC Voltage Follower: National Semiconductor Application Note (app note added 2/06)

Micropower Buffered Rail-to-Rail Adjustable Volatge Source: Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc. (app note added 6/06)

Rail-to-Rail Voltage Follower/Buffer: Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc. (app note added 6/06)

High Input Impedance Source Follower: Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc. (app note added 6/06)

LB-11: The LM110: An Improved IC Voltage Follower: National Semiconductor Application Note (app note added 2/06)

Base Current Compensated High Voltage Amplifier: Unpublished 1995 The base current of a single transistor high voltage amplifier varies from unit to unit and over temperature and current. To compensate, this opamp circuit measures base current and adds an equal but opposite current to input. (added 9/04)

A New Current-Differencing Quad of Plus or Minus Input Amplifiers: National Semiconductor - Application Note (added 2/06)

AN-1110:LVDS Quad Dynamic I Cc Vs Frequency: National Semiconductor - Application Note (added 2/06)

Get More Power Out of Dual or Quad Op-Amps: National Semiconductor - Application Note (added 2/06)

LM139/LM239/LM339 a Quad of Independently Functioning Comparators: National Semiconductor - Application Note (added 2/06)

Quad MOSFET Drivers for High: Supertex Semiconductors (app note added 2/06)

Quad Output Switching Converter Provides Power for Large TFT LCD Panels: DN349 - Design Notes (Linear Technology) (added 1/06)

CLC730145, CLC730132 (Soic and Tssop) Quad High-Speed Buffer Evaluation Boards: National Semiconductor - Application Note (added 2/06)

Laser Communication System: This is a simple Laser communication system. It can transmit and receive signal from any audio device.Communication distance is few meters. All components are not critical. Transistor 2N2222 may be on the coolrib. Laser diode is from laser pointer (Electronic circuit design added 02/05)

Cold Activated Switch: The thermistor used has a resistance of 15k at 25 degrees and 45k at 0 degrees celsius. A suitable bead type thermistor is found in the Maplin catalogue. The 100k pot allows this circuit to trigger over a wide range of temperatures. A slight amount of hysteresis is provided by inclusion of the 270k resistor. This prevents relay chatter when temperature is near the switching threshold of this circuit. (added 2/06)

Frost Alarm #3: (schematic / circuit design added 9/02)

Fridge Door Alarm: (circuit added 9/04)

Laser Link Communicator: audio transmission up to few hundred meters (Circuit / schematic design added 6/06)

4 Hints for Making Better Microwave Counter Measurements: Agilent Application Note (Circuit / schematic design added 6/06)