Op Amp Circuit Collection

Transcription

1 Op Amp Circuit Collection Note: National Semiconductor recommends replacing 2N2920 and 2N3728 matched pairs with LM394 in all application circuits. Section 1 Basic Circuits Inverting Amplifier Difference Amplifier For minimum offset error due to input bias current National Semiconductor Application Note 31 September 2002 Non-Inverting Amplifier Inverting Summing Amplifier R5 = R1//R2//R3//R4 For minimum offset error due to input bias current Op Amp Circuit Collection AN National Semiconductor Corporation AN

2 AN-31 Section 1 Basic Circuits (Continued) Non-Inverting Summing Amplifier Inverting Amplifier with High Input Impedance *R S = 1k for 1% accuracy *Source Impedance less than 100k gives less than 1% gain error. Fast Inverting Amplifier with High Input Impedance Non-Inverting AC Amplifier

3 Section 1 Basic Circuits (Continued) AN-31 Practical Differentiator Integrator For minimum offset error due to input bias current Fast Integrator Current to Voltage Converter V OUT =l IN R1 *For minimum error due to bias current R2 = R

4 AN-31 Section 1 Basic Circuits (Continued) Circuit for Operating the LM101 without a Negative Supply Circuit for Generating the Second Positive Voltage Neutralizing Input Capacitance to Optimize Response Time Voltage Comparator for Driving DTL or TTL Integrated Circuits Threshold Detector for Photodiodes Integrator with Bias Current Compensation *Adjust for zero integrator drift. Current drift typically 0.1 n/a C over 55 C to 125 C temperature range. 4

5 Section 1 Basic Circuits (Continued) AN-31 Double-Ended Limit Detector V OUT = 4.6V for V LT V IN V UT V OUT = 0V for V IN < V LT or V IN > V UT Multiple Aperture Window Discriminator

6 AN-31 Section 1 Basic Circuits (Continued) Offset Voltage Adjustment for Inverting Amplifiers Using Any Type of Feedback Element Offset Voltage Adjustment for Non-Inverting Amplifiers Using Any Type of Feedback Element Offset Voltage Adjustment for Voltage Followers Offset Voltage Adjustment for Differential Amplifiers

7 Section 1 Basic Circuits (Continued) AN-31 Offset Voltage Adjustment for Inverting Amplifiers Using 10 kω Source Resistance or Less Section 2 Signal Generation Low Frequency Sine Wave Generator with Quadrature Output

8 AN-31 Section 2 Signal Generation (Continued) High Frequency Sine Wave Generator with Quadrature Output Free-Running Multivibrator Wein Bridge Sine Wave Oscillator *Chosen for oscillation at 100 Hz *Eldema V, 14 ma Bulb 8

9 Section 2 Signal Generation (Continued) AN-31 Function Generator Pulse Width Modulator

10 AN-31 Section 2 Signal Generation (Continued) Bilateral Current Source Bilateral Current Source

11 Section 2 Signal Generation (Continued) AN-31 Wein Bridge Oscillator with FET Amplitude Stabilization

12 AN-31 Section 2 Signal Generation (Continued) Low Power Supply for Integrated Circuit Testing *V OUT = 1V/kΩ Positive Voltage Reference Positive Voltage Reference

13 Section 2 Signal Generation (Continued) AN-31 Negative Voltage Reference Negative Voltage Reference Precision Current Sink Precision Current Source

14 AN-31 Section 3 Signal Processing Differential-Input Instrumentation Amplifier Variable Gain, Differential-Input Instrumentation Amplifier *Gain adjust A V =10 4 R

15 Section 3 Signal Processing (Continued) AN-31 Instrumentation Amplifier with ±100 Volt Common Mode Range Matching determines common mode rejection

16 AN-31 Section 3 Signal Processing (Continued) Instrumentation Amplifier with ±10 Volt Common Mode Range High Input Impedance Instrumentation Amplifier * Matching Determines CMRR May be deleted to maximize bandwidth 16

17 Section 3 Signal Processing (Continued) AN-31 Bridge Amplifier with Low Noise Compensation *Reduces feed through of power supply noise by 20 db and makes supply bypassing unnecessary. Trim for best common mode rejection Gain adjust Bridge Amplifier Precision Diode Precision Clamp Fast Half Wave Rectifier *E REF must have a source impedance of less than 200Ω if D2 is used

18 AN-31 Section 3 Signal Processing (Continued) Precision AC to DC Converter *Feedforward compensation can be used to make a fast full wave rectifier without a filter Low Drift Peak Detector

19 Section 3 Signal Processing (Continued) AN-31 Absolute Value Amplifier with Polarity Detector Sample and Hold *Polycarbonate-dielectric capacitor

20 AN-31 Section 3 Signal Processing (Continued) Sample and Hold *Worst case drift less than 2.5 mv/sec Teflon, Polyethylene or Polycarbonate Dielectric Capacitor Low Drift Integrator *Q1 and Q3 should not have internal gate-protection diodes. Worst case drift less than 500 µv/sec over 55 C to +125 C

21 Section 3 Signal Processing (Continued) AN-31 Fast Summing Amplifier with Low Input Current *In addition to increasing speed, the LM101A raises high and low frequency gain, increases output drive capability and eliminates thermal feedback. Power Bandwidth: 250 khz Small Signal Bandwidth: 3.5 MHz Slew Rate: 10V/µs Fast Integrator with Low Input Current

22 AN-31 Section 3 Signal Processing (Continued) Adjustable Q Notch Filter

23 Section 3 Signal Processing (Continued) AN-31 Easily Tuned Notch Filter Tuned Circuit Two-Stage Tuned Circuit

24 AN-31 Section 3 Signal Processing (Continued) Negative Capacitance Multiplier Variable Capacitance Multiplier

25 Section 3 Signal Processing (Continued) AN-31 Simulated Inductor Capacitance Multiplier L R1 R2 C1 R S =R2 R P =R High Pass Active Filter *Values are for 100 Hz cutoff. Use metalized polycarbonate capacitors for good temperature stability Low Pass Active Filter *Values are for 10 khz cutoff. Use silvered mica capacitors for good temperature stability

26 AN-31 Section 3 Signal Processing (Continued) Nonlinear Operational Amplifier with Temperature Compensated Breakpoints Current Monitor

27 Section 3 Signal Processing (Continued) AN-31 Saturating Servo Preamplifier with Rate Feedback Power Booster

28 AN-31 Section 3 Signal Processing (Continued) Analog Multiplier Long Interval Timer Fast Zero Crossing Detector *Low leakage µf per second delay Propagation delay approximately 200 ns DTL or TTL fanout of three Minimize stray capacitance Pin

29 Section 3 Signal Processing (Continued) AN-31 Amplifier for Piezoelectric Transducer Temperature Probe *Set for 0V at 0 C Adjust for 100 mv/ C Low frequency cutoff = R1 C Photodiode Amplifier Photodiode Amplifier V OUT =R1I D V OUT = 10 V/µA *Operating photodiode with less than 3 mv across it eliminates leakage currents. High Input Impedance AC Follower

30 AN-31 Section 3 Signal Processing (Continued) Temperature Compensated Logarithmic Converter 10 na < I IN < 1mA Sensitivity is 1V per decade 1 kω (±1%) at 25 C, ppm/ C. Available from Vishay Ultronix, Grand Junction, CO, Q81 Series. *Determines current for zero crossing on output: 10 µa as shown Root Extractor * 2N3728 matched pairs

31 Section 3 Signal Processing (Continued) AN-31 Multiplier/Divider Cube Generator

32 AN-31 Section 3 Signal Processing (Continued) Fast Log Generator 1 kω (±1%) at 25 C, ppm/ C. Available from Vishay Ultronix, Grand Junction, CO, Q81 Series Anti-Log Generator 1 kω (±1%) at 25 C, ppm/ C. Available from Vishay Ultronix, Grand Junction, CO, Q81 Series

33 LIFE SUPPORT POLICY Notes NATIONAL S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. National Semiconductor Corporation Americas support@nsc.com National Semiconductor Europe Fax: +49 (0) europe.support@nsc.com Deutsch Tel: +49 (0) English Tel: +44 (0) Français Tel: +33 (0) A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Asia Pacific Customer Response Group Tel: Fax: ap.support@nsc.com National Semiconductor Japan Ltd. Tel: Fax: Op Amp Circuit Collection AN-31 National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.