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 -55C to +125C temperature range. The LM725C has slightly relaxed specifications and has its performance guaranteed over a 0C to 70C temperature range. n n n n n n n n n Connection Diagram Typical Applications Metal Can Package High open loop gain 3,000,000 Low input voltage drift 0.6 V/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 Thermocouple Amplifier DS010474-1 Order Number LM725H/883, LM725CH or LM725AH/883 See NS Package Number H08C Dual-In-Line Package DS010474-10 DS010474-2 Order Number LM725CN See NS Package Number N08E (c) 2000 National Semiconductor Corporation DS010474 www.national.com LM725 Operational Amplifier August 2000 LM725 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 260C 150C Operating Temperature Range 22V 500 mW 5V 22V -65C to +150C TA(MAX) TA(MIN) LM725 -55C to +125C LM725A -55C to +125C LM725C 0C to +70C Electrical Characteristics (Note 4) Parameter Conditions LM725A Min Input Offset Voltage TA = 25C, (Without External Trim) RS 10 k LM725 Typ Max Min LM725C Typ Max 0.5 0.5 Min Units Typ Max 1.0 0.5 2.5 mV Input Offset Current TA = 25C 2.0 5.0 2.0 20 2.0 35 nA Input Bias Current TA = 25C 42 80 42 100 42 125 nA Input Noise Voltage TA = 25C 15 15 15 nV/Hz fo = 100 Hz 9.0 9.0 9.0 nV/Hz fo = 1 kHz 8.0 8.0 8.0 nV/Hz fo = 10 Hz 1.0 1.0 1.0 pA/Hz fo = 100 Hz 0.3 0.3 0.3 pA/Hz fo = 1 kHz 0.15 0.15 0.15 pA/Hz fo = 10 Hz Input Noise Current TA = 25C Input Resistance TA = 25C Input Voltage Range TA = 25C Large Signal Voltage Gain TA = 25C, RL 2 k, 1.5 M 13.5 14 1.5 13.5 14 1.5 13.5 14 V 1000 3000 1000 3000 250 3000 V/mV 110 120 94 120 dB VOUT = 10V Common-Mode TA = 25C, Rejection Ratio RS 10 k Power Supply TA = 25C, Rejection Ratio RS 10 k Output Voltage Swing TA = 25C, RL 10 k RL 2 k Power Consumption TA = 25C Input Offset Voltage RS 10 k 120 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 V/V V V 150 mW 3.5 mV (Without External Trim) Average Input Offset RS = 50 Voltage Drift 2.0 2.0 1.0 0.6 5.0 2.0 V/C 0.6 V/C (Without External Trim) Average Input Offset RS = 50 Voltage Drift 0.6 (With External Trim) Input Offset Current TA = TMAX 1.2 4.0 1.2 20 1.2 35 nA TA = TMIN 7.5 18.0 7.5 40 4.0 50 nA 35 90 35 150 10 Average Input Offset pA/C Current Drift Input Bias Current www.national.com TA = TMAX 20 70 20 100 125 nA TA = TMIN 80 180 80 200 250 nA 2 Parameter Conditions (Continued) LM725A Min Large Signal Voltage Gain LM725 Electrical Characteristics (Note 4) LM725 Typ Max Min LM725C Typ Max Min Units Typ Max RL 2 k TA = TMAX 1,000,000 1,000,000 125,000 500,000 250,000 125,000 110 100 V/V RL 2 k TA = TMIN Common-Mode RS 10 k V/V 115 dB 20 V/V Rejection Ratio Power Supply RS 10 k 8.0 20 Rejection Ratio Output Voltage Swing RL 2 k 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 150C/W for operation at ambient temperatures above 75C. 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 LM725 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 Power Consumption vs Temperature LM725 Typical Performance Characteristics (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 LM725 Auxiliary Circuits Voltage Offset Null Circuit DS010474-3 Frequency Compensation Circuit DS010474-4 Compensation Component Values AV R1 C1 R2 C2 () (F) () (F) 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 LM725 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 LM725 Typical Applications (Continued) 100V Common Mode Range Differential Amplifier DS010474-11 Instrumentation Amplifier with High Common Mode Rejection DS010474-12 www.national.com 8 LM725 Typical Applications (Continued) Precision Amplifier AVCL = 1000 DS010474-13 9 www.national.com LM725 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 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 Tel: 1-800-272-9959 Fax: 1-800-737-7018 Email: support@nsc.com www.national.com National Semiconductor Europe Fax: +49 (0) 180-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 69 9508 6208 English Tel: +44 (0) 870 24 0 2171 Francais Tel: +33 (0) 1 41 91 87 90 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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