LM725 Operational Amplifier General Description Features The LM725/LM725A/LM725C are operational amplifiers featuring superior performance in applications where low noise, low drift, and accurate closed-loop gain are required. With high common mode rejection and offset null capability, it is especially suited for low level instrumentation applications over a wide supply voltage range. The LM725A has tightened electrical performance with higher input accuracy and like the LM725, is guaranteed over a −55˚C to +125˚C temperature range. The LM725C has slightly relaxed specifications and has its performance guaranteed over a 0˚C to 70˚C temperature range. n n n n n n n n n High open loop gain 3,000,000 Low input voltage drift 0.6 µV/˚C High common mode rejection 120 dB Low input noise current 0.15 pA/√Hz Low input offset current 2 nA High input voltage range ± 14V Wide power supply range ± 3V to ± 22V Offset null capability Output short circuit protection Connection Diagrams Metal Can Package Dual-In-Line Package DS010474-2 Order Number LM725CN See NS Package Number N08E DS010474-1 Order Number LM725H/883, LM725CH or LM725AH/883 See NS Package Number H08C © 1999 National Semiconductor Corporation DS010474 www.national.com LM725 Operational Amplifier May 1998 Absolute Maximum Ratings (Note 1) Lead Temperature (Soldering, 10 Sec.) Maximum Junction Temperature If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage Internal Power Dissipation (Note 2) Differential Input Voltage Input Voltage (Note 3) Storage Temperature Range 260˚C 150˚C Operating Temperature Range ± 22V 500 mW ± 5V ± 22V −65˚C to +150˚C TA(MAX) TA(MIN) LM725 −55˚C to +125˚C LM725A −55˚C to +125˚C LM725C 0˚C to +70˚C Electrical Characteristics (Note 4) Parameter Conditions LM725A Min Input Offset Voltage TA = 25˚C, (Without External Trim) RS ≤ 10 kΩ TA = 25˚C TA = 25˚C Input Offset Current Input Bias Current Input Noise Voltage Input Noise Current Input Resistance Input Voltage Range Large Signal Voltage Gain Common-Mode Rejection Ratio Power Supply Min LM725C Typ Max 0.5 0.5 2.0 5.0 42 80 Min Units Typ Max 1.0 0.5 2.5 mV 2.0 20 2.0 35 nA 42 100 42 125 nA TA = 25˚C fo = 10 Hz fo = 100 Hz 15 15 15 nV/√Hz 9.0 9.0 9.0 nV/√Hz fo = 1 kHz 8.0 8.0 8.0 nV/√Hz TA = 25˚C fo = 10 Hz 1.0 1.0 1.0 pA/√Hz 0.3 0.3 0.3 pA/√Hz 0.15 0.15 0.15 pA/√Hz 1.5 1.5 1.5 MΩ fo = 100 Hz fo = 1 kHz TA = 25˚C TA = 25˚C TA = 25˚C, ± 13.5 ± 14 ± 13.5 ± 14 ± 13.5 ± 14 V RL ≥ 2 kΩ, VOUT = ± 10V TA = 25˚C, 1000 3000 1000 3000 250 3000 V/mV 110 120 94 120 dB 120 RS ≤ 10 kΩ TA = 25˚C, Output Voltage Swing RS ≤ 10 kΩ TA = 25˚C, Power Consumption RL ≥ 2 kΩ TA = 25˚C Input Offset Voltage RS ≤ 10 kΩ Rejection Ratio LM725 Typ Max RL ≥ 10 kΩ 2.0 ± 12.5 ± 12.0 5.0 ± 13.5 ± 13.5 80 2.0 ± 12 ± 10 105 10 ± 13.5 ± 13.5 80 0.7 2.0 ± 12 ± 10 105 35 ± 13.5 ± 13.5 80 1.5 µV/V V V 150 mW 3.5 mV (Without External Trim) Average Input Offset RS = 50Ω Voltage Drift 2.0 2.0 5.0 2.0 µV/˚C 1.0 0.6 0.6 µV/˚C 1.2 4.0 1.2 20 1.2 35 7.5 18.0 7.5 40 4.0 50 35 90 35 150 10 20 70 20 100 125 nA 80 180 80 200 250 nA (Without External Trim) Average Input Offset RS = 50Ω Voltage Drift 0.6 (With External Trim) Input Offset Current TA = TMAX TA = TMIN Average Input Offset nA nA pA/˚C Current Drift Input Bias Current www.national.com TA = TMAX TA = TMIN 2 Electrical Characteristics (Note 4) Parameter Conditions (Continued) LM725A Min Large Signal Voltage Gain Common-Mode LM725 Typ Max Min LM725C Typ Max Min RL ≥ 2 kΩ TA = TMAX 1,000,000 1,000,000 125,000 RL ≥ 2 kΩ TA = TMIN 500,000 250,000 125,000 110 100 RS ≤ 10 kΩ Units Typ Max V/V V/V 115 dB 20 µV/V Rejection Ratio Power Supply RS ≤ 10 kΩ 8.0 20 Rejection Ratio Output Voltage Swing RL ≥ 2 kΩ ± 12 ± 10 ± 10 V Note 1: “Absolute Maximum Ratings” indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is functional, but do not guarantee specific performance limits. Note 2: Derate at 150˚C/W for operation at ambient temperatures above 75˚C. Note 3: For supply voltages less than ± 22V, the absolute maximum input voltage is equal to the supply voltage. Note 4: These specifications apply for VS = ± 15V unless otherwise specified. Note 5: For Military electrical specifications RETS725AX are available for LM725AH and RETS725X are available for LM725H. Schematic Diagram DS010474-5 3 www.national.com Typical Performance Characteristics Voltage Gain vs Temperature for Supply Voltages Change in Trimmed Input Offset Voltage vs Temperature DS010474-15 Input Offset Current vs Temperature Untrimmed Input Offset Voltage vs Temperature DS010474-17 DS010474-16 Input Bias Current vs Temperature DS010474-18 Stabilization Time of Input Offset Voltage from Power Turn-On DS010474-19 DS010474-20 Change in Input Offset Voltage Due to Thermal Shock vs Time Input Noise Voltage vs Frequency Input Noise Current vs Frequency DS010474-22 DS010474-21 www.national.com 4 DS010474-23 Typical Performance Characteristics Power Consumption vs Temperature (Continued) Open Loop Frequency Response for Values of Compensation (Note 6) Values for Suggested Compensation Networks vs Various Close Loop Voltage Gains DS010474-24 DS010474-25 Frequency Response for Various Close Loop Gain (Note 6) Output Voltage Swing vs Frequency (Note 6) DS010474-26 Transient Response DS010474-29 DS010474-28 DS010474-27 Note 6: Performance is shown using recommended compensation networks. Transient Response Test Circuit DS010474-8 5 www.national.com Auxiliary Circuits Voltage Offset Null Circuit DS010474-3 Frequency Compensation Circuit DS010474-4 Compensation Component Values AV R1 C1 R2 C2 (Ω) (µF) (Ω) (µF) 10,000 10k 50 pF 1,000 470 0.001 100 47 0.01 10 27 0.05 270 0.0015 1 10 0.05 39 0.02 www.national.com 6 Typical Applications Photodiode Amplifier DS010474-9 DC Gains = 10,000; 1,000; 100; and 10 Bandwidth = Determined by value of C1 Thermocouple Amplifier DS010474-10 Note: Indicates ± 1% metal film resistors recommended for temperature stability. 7 www.national.com Typical Applications (Continued) ± 100V Common Mode Range Differential Amplifier DS010474-11 Instrumentation Amplifier with High Common Mode Rejection DS010474-12 www.national.com 8 Typical Applications (Continued) Precision Amplifier AVCL = 1000 DS010474-13 9 www.national.com Physical Dimensions inches (millimeters) unless otherwise noted Order Number LM725H/883, LM725CH or LM725AH/883 NS Package Number H08C Order Number LM725CN NS Package Number N08E www.national.com 10 LM725 Operational Amplifier Notes LIFE SUPPORT POLICY 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 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 Tel: 1-800-272-9959 Fax: 1-800-737-7018 Email: [email protected] www.national.com National Semiconductor Europe Fax: +49 (0) 1 80-530 85 86 Email: [email protected] Deutsch Tel: +49 (0) 1 80-530 85 85 English Tel: +49 (0) 1 80-532 78 32 Français Tel: +49 (0) 1 80-532 93 58 Italiano Tel: +49 (0) 1 80-534 16 80 2. 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. 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