Section 1-Basic CircuitsSection 2 - Signal GenerationLow Power Supply for Integrated Circuit TestingSection 3 - Signal ProcessingOp Amp Circuit CollectionNote: National Semiconductor recommends replacing 2N2920 and 2N3728 matched pairs with LM394 in all applicationcircuits.Section 1—Basic CircuitsInverting Amplifier Non-Inverting Amplifier0070570100705702Difference Amplifier Inverting Summing Amplifier00705703For minimum offset error due to input bias current00705704R5 = R1//R2//R3//R4For minimum offset error due to input bias currentNational SemiconductorApplication Note 31September 2002Op Amp Circuit Collection AN-31© 2002 National Semiconductor Corporation AN007057 www.national.comSection 1—Basic Circuits (Continued)Non-Inverting Summing Amplifier Inverting Amplifier with High Input Impedance00705705*RS= 1k for 1% accuracy00705706*Source Impedance less than 100k gives less than 1% gain error.Fast Inverting Amplifier with High Input Impedance Non-Inverting AC Amplifier0070570700705708AN-31www.national.com 2Section 1—Basic Circuits (Continued)Practical Differentiator Integrator0070570900705710For minimum offset error due to input bias currentFast Integrator Current to Voltage Converter0070571100705712VOUT=lINR1*For minimum error due to bias current R2 = R1AN-31www.national.com3Section 1—Basic Circuits (Continued)Circuit for Operating the LM101without a Negative SupplyCircuit for Generating theSecond Positive Voltage0070571300705714Neutralizing Input Capacitanceto Optimize Response Time00705715Integrator with Bias Current Compensation00705716*Adjust for zero integrator drift.Current drift typically 0.1 n/A˚C over −55˚C to 125˚C temperature range.Voltage Comparator for DrivingDTL or TTL Integrated Circuits00705717Threshold Detector for Photodiodes00705718AN-31www.national.com 4Section 1—Basic Circuits (Continued)Double-Ended Limit Detector00705719VOUT= 4.6V for VLT≤ VIN≤ VUTVOUT= 0V for VIN<VLTor VIN>VUTMultiple Aperture Window Discriminator00705720AN-31www.national.com5Section 1—Basic Circuits (Continued)Offset Voltage Adjustment for Inverting Amplifiers UsingAny Type of Feedback ElementOffset Voltage Adjustment for Non-Inverting AmplifiersUsing Any Type of Feedback Element0070572100705722Offset Voltage Adjustment for Voltage Followers Offset Voltage Adjustment for Differential Amplifiers0070572300705724AN-31www.national.com 6Section 1—Basic Circuits (Continued)Offset Voltage Adjustment for Inverting Amplifiers Using 10 kΩ Source Resistance or Less00705725Section 2 — Signal GenerationLow Frequency Sine Wave Generator with Quadrature Output00705726AN-31www.national.com7Section 2 — Signal Generation (Continued)High Frequency Sine Wave Generator with Quadrature Output00705727Free-Running Multivibrator Wein Bridge Sine Wave Oscillator00705728*Chosen for oscillation at 100 Hz00705729*Eldema 1869 10V, 14 mA BulbAN-31www.national.com 8Section 2 — Signal Generation (Continued)Function Generator00705730Pulse Width Modulator00705731AN-31www.national.com9Section 2 — Signal Generation (Continued)Bilateral Current Source Bilateral Current Source0070573200705733AN-31www.national.com 10Section 2 — Signal Generation (Continued)Wein Bridge Oscillator with FET Amplitude Stabilization00705734AN-31www.national.com11Section 2 — Signal Generation (Continued)Low Power Supply for Integrated Circuit Testing0070573500705791*VOUT= 1V/kΩPositive Voltage Reference Positive Voltage Reference0070573600705737AN-31www.national.com 12Section 2 — Signal Generation (Continued)Negative Voltage Reference Negative Voltage Reference0070573800705739Precision Current Sink Precision Current Source0070574000705741AN-31www.national.com13Section 3 — Signal ProcessingDifferential-Input Instrumentation Amplifier00705742Variable Gain, Differential-Input Instrumentation Amplifier00705743*Gain adjustAV= 10−4R6AN-31www.national.com 14Section 3 — Signal Processing (Continued)Instrumentation Amplifier with±100 Volt Common Mode Range00705744†Matching determines common mode rejection.AN-31www.national.com15Section 3 — Signal Processing (Continued)Instrumentation Amplifier with±10 Volt Common Mode Range00705745High Input Impedance Instrumentation Amplifier00705746*†Matching Determines CMRR‡May be deleted to maximize bandwidthAN-31www.national.com 16Section 3 — Signal Processing (Continued)Bridge Amplifier with Low Noise Compensation00705747*Reduces feed through of power supply noise by 20 dB and makes supply bypassing unnecessary.†Trim for best common mode rejection‡Gain adjustBridge Amplifier Precision Diode0070574800705749Precision Clamp Fast Half Wave Rectifier00705750*EREFmust have a source impedance of less than 200Ω if D2 is used.00705751AN-31www.national.com17Section 3 — Signal Processing (Continued)Precision AC to DC Converter00705752*Feedforward compensation can be used to make a fast full wave rectifier without a filter.Low Drift Peak Detector00705753AN-31www.national.com 18Section 3 — Signal Processing (Continued)Absolute Value Amplifier with Polarity Detector00705754Sample and Hold00705755*Polycarbonate-dielectric capacitorAN-31www.national.com19Section 3 — Signal Processing (Continued)Sample and Hold00705756*Worst case drift less than 2.5 mV/sec†Teflon, Polyethylene or Polycarbonate Dielectric CapacitorLow Drift Integrator00705757*Q1 and Q3 should not have internal gate-protection diodes.Worst case drift less than 500 µV/sec over −55˚C to +125˚C.AN-31www.national.com 20Section 3 — Signal Processing (Continued)Fast†Summing Amplifier with Low Input Current00705758*In addition to increasing speed, the LM101A raises high and low frequency gain, increases output drive capability and eliminates thermal feedback.†Power Bandwidth: 250 kHzSmall Signal Bandwidth: 3.5 MHzSlew Rate: 10V/µsFast Integrator with Low Input Current00705759AN-31www.national.com21Section 3 — Signal Processing (Continued)Adjustable Q Notch Filter00705760AN-31www.national.com 22Section 3 — Signal Processing (Continued)Easily Tuned Notch Filter Tuned Circuit0070576100705762Two-Stage Tuned Circuit00705763AN-31www.national.com23Section 3 — Signal Processing (Continued)Negative Capacitance Multiplier00705765Variable Capacitance Multiplier00705766AN-31www.national.com 24Section 3 — Signal Processing (Continued)Simulated Inductor Capacitance Multiplier00705767L ≥ R1 R2 C1RS= R2RP= R100705768High Pass Active Filter00705771*Values are for 100 Hz cutoff. Use metalized