Timer Exploits OpAmp Bias Current - 07/21/94 EDN-Design Ideas The simple, low-cost analog timer in Fig 1 exploits the parasitic input-bias current of op-amp IC1. The timer achieves long time delays even though it uses only low-value, inexpensive ceramic chip capacitors. After all, because the input-bias current is the minimum current flow into an op amp, Design by Aleksandr Belousov, Baltimore, MD
Tiny 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 __ Electronics Projects for You
Transimpedance Amplifier - You may have noticed that most circuits work on a convenient principle: Voltage In, Voltage Out. But, what about the large class of sensors, such as a photodiode, that produce a current? Photodiodes may be called into action for applications such as precision light meters or high-speed fiber-optic receivers. If you need to amplify the signal from this type of sensor, you must first convert this current to a useful voltage (spice design)
Transimpedance synchronous Amplification nulls out background illumination - 12/03/07 EDN-Design Ideas In optical spectroscopy a correct intensity measurement of the probe beam is fundamental during material characterizationLight sensors find use in a host of important applications, spanning from consumer electronics, such as ambient-light measurements Design by Stefano Salvatori and Gennaro Conte, University Roma Tre, Rome, Italy; Editedby Charles H Small and Fran Granville-December 3, 2007
True op-amp made from inverters - 11/18/13 EDN-Design Ideas Designs that stretch parts beyond their intended use, like this true op-amp constructed from eight CMOS
inverters, have a certain special appeal Design by Colin Weltin-Wu
Two Op Amps Provide Averaged Absolute Value - 30-Oct-03 EDN-Design Ideas The circuit in Figure 1 is useful when you need amplitude demodulation or an averaged absolute-value conversion. The circuit comprises two stages, the first of which, IC1A, is a differential-output absolute-value converter. The second stage, IC1B, is a traditional differential amplifier. The combination of the two stages performs single-ended absolute-value conversion but only if R3>>R2 Design by Dobromir Dobrev, Jet Electronics, Sofia, Bulgaria
Two OpAmps Make Fast Full Wave Rectifier - 03/14/96 EDN-Design Ideas The circuit in Figure 1 is a precision full-wave rectifier with the following characteristics. Design by Fernando Werlang, CPqD-Telebras, Campinas, Brazil
Two-Op Amps Provide Averaged Absolute Value - 10/30/03 EDN-Design Ideas The circuit in Figure 1 is useful when you need amplitude demodulation or an averaged absolute-value conversion. The circuit comprises two stages, the first of which, IC1A, is a differential-output absolute-value converter. The sec Design by Dobromir Dobrev, Jet Electronics, Sofia, Bulgaria
Typical Single-Ended to Differential Conversion - Basic Single-Ended to Differential Conversion Circuit Example which shows a gain of 10 with no external resistors to set the gain. The resistors are factory trimmed to give a very accurate gain and the gain setting resistors are closely matched to maximize CMRR. A voltage applied to the Vocm pin sets the offset. __ Linear Technology/Analog Devices App Note, Jul 2, 2012
Ultra Long Time constant Integrator - Circuit Ideas for Designers App Note __ Advanced Linear Devices, Inc
Ultra Low Noise Op Amp Combines Chopper & Bipolar Op Amps - DN36 Design Notes __ Linear Technology/Analog Devices
Ultra Low Voltage Differential Amplifier - Circuit Ideas for Designers App Note __ Advanced Linear Devices, Inc
Ultra-Low Noise Low Distortion Audio Op Amp - LT1115 __ Linear Technology/Analog Devices
Ultraprecise Current Sensing with LTC6102 - Very low input offset allows using low value resistors while maintaining high measurement resolution. Using low value also reduces power losses and temperature rise. __ Linear Technology/Analog Devices App Note, Jul 2, 2012
Ultra-Precision, Wide Dynamic Range 10Hz Bandwidth Photodiode Amplifier - The low input bias current and input noise current, combined with low voltage offset, provide a precision signal monitor. A high degree of input sensitivity is provided to the circuit by the large dynamic range, characterized by low input offset and high DC gain of the LTC2054. __ Linear Technology/Analog Devices App Note, Mar 22nd 2010
Unique IC Buffer Enhances Op Amp Designs Tames Fast Amplifiers - AN16 Linear Technology This note describes some of the unique IC design techniques incorporated into a fast, monolithic power buffer, the LT1010. Also, some application ideas are described such as capacitive load driving, boosting fast op amp output current and power supply circuits. __ Linear Technology/Analog Devices
Use a Self-Powered Op Amp to Create a Low-Leakage Rectifier - 10/20/11 EDN-Design Ideas An amplifier that works at 0.8V is key. You can combine a carefully chosen op amp, a low-threshold P-channel MOSFET, and two feedback resistors to make a rectifier circuit with less forward drop than a diode (Figure 1). The rectified output voltage powers the active circuitry, so no additional power supply is necessary. Design by Martin Tomasz, Sageloop Designs, San Francisco, CA
Use an Integrator Instead Of Coupling Capacitors - 02/16/12 EDN-Design Ideas Level-shift a signal with an unknown dc offset to a known offset without ac coupling. An ultrasonic sensor circuit requiring self-adjustment to the level of an ac-input signal also must accommodate the signal’s unknown and variable dc-bias voltage. The circuit cannot use an ac coupling capacitor, and the resulting output must be level-shifted to a known dc offset. The design uses a dc-offset compensator (Figure 1). Design by Vladimir Rentyuk, Modul-98 Ltd, Zaporozhye, Ukraine
Use an Op Amp as a Set/Reset Flip-Flop - 05/24/12 EDN-Design Ideas Eliminate a flip-flop package by using a spare op amp for an SR latch function. You can make a set/reset flip-flop from two NAND or NOR gates or use readily available set/reset flip-flop ICs, such as the 74HC279 quad-set/reset latch. The drawback of these methods is that they require a large amount of space to form the flip-flop. Even if you need only one flip-flop, you must use a large IC package with this approach. However, you can use a spare rail-to-rail op amp to perform the needed latch function (Figure 1). Design by Aruna Rubasinghe
Use dual Op Amp in an instrumentation Amp - 01/18/07 EDN-Design Ideas Use op amps of your choice in an instrumentation amplifier Design by Jerald Graeme, Burr-Brown Corp, Tucson, AZ
Use Op Amps to Make Automatic-Oring Power Selector - 08/11/11 EDN-Design Ideas Replace diodes with FETs to reduce power loss. Many systems must select among two or more low-voltage dc-input sources, such as an ac adapter, a USB (Universal Serial Bus) port, or an onboard battery, for example. You can implement this selection using manual switches, but automatic switching is preferable. You usually want to use the highest-available input voltage to power your system. You can accomplish this task using a Schottky-diode ORing scheme (Figure 1). Unfortunately, the forward-voltage drop of a Schottky diode ranges from 300 to 600 mV. This voltage wastes power, creates heat, and decreases the voltage available to your system. Design by Bob Zwicker, Analog Devices, Fort Collins, CO
Use op-amp injection for Bode analysis - 16-Sep-04 EDN-Design Ideas Bode analysis is an excellent way to measure small-signal stability and loop response in power-supply designs. Bode analysis monitors gain and phase of a control loop. It performs this monitoring by breaking the feedback loop and injecting a signal into the feedback node and then comparing the injected signal with the output signal of the control loop Design by Martin Galinski
Using All four Amplifiers of the LT1397 to Drive Large zCapacitive Loads - Four paralleled amplifiers increase load capacitor current drive capability. A small ballast resistor at each output increases isolates the effects of each amplifier's different output offset. __ Linear Technology/Analog Devices App Note, Jun 29th 2012
Using the LTC Op Amp Macromodels - AN48 LTC's op amp macromodels are described in detail, along with the theory behind each model and complete schematics of each topology. Extended modeling topics are discussed, such as phase/frequency response modifications and asymmetric slew rate for JFET op amp models __ Linear Technology/Analog Devices |