LM381N

LM381 LM381A Low Noise Dual Preamplifier July 1987 LM381 LM381A Low Noise Dual Preamplifier General Description The LM381 LM381A is a dual preamplifier for the amplification of low level signals in applications requiring optimum noise performance Each of the two amplifiers is completely independent with individual internal power supply decoupler-regulator providing 120 dB supply rejection and 60 dB channel separation Other outstanding features include high gain (112 dB) large output voltage swing (VCC b 2V) p-p and wide power bandwidth (75 kHz 20 Vp-p) The LM381 LM381A operates from a single supply across the wide range of 9V to 40V Either differential input or single ended input configurations may be selected The amplifier is internally compensated with the provision for additional external compensation for narrow band applications For additional information see AN-64 AN-104 Features Y Y Y Y Y Y Y Y Y Y Low noise 0 5 mV total input noise High gain 112 dB open loop Single supply operation Wide supply range 9V – 40V Power supply rejection 120 dB Large output voltage swing (VCC b 2V)p-p Wide bandwidth 15 MHz unity gain Power bandwidth 75 kHz 20 Vp-p Internally compensated Short circuit protected Schematic Diagram TL H 7841 – 1 C1995 National Semiconductor Corporation TL H 7841 RRD-B30M115 Printed in U S A Absolute Maximum Ratings If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications Supply Voltage Power Dissipation (Note 1) a 40V Operating Temperature Range Storage Temperature Range Lead Temperature (Soldering 10 sec ) 0 C to a 70 C b 65 C to a 150 C 260 C 1 56 W VCC e 14V unless otherwise stated Min Typ 160 000 320 000 10 100 200 05 Open Loop Source Sink 150 8 2 VCC b 2 15 20 VPP (VCC e 24V) Linear Operation f e 1 kHz f e 1 kHz 60 dB Gain f e 1 kHz RS e 60X 10–10 000 Hz (Single Ended Input Flat Gain Circuit AV e 1000) 05 05 07 10 mVrms mVrms 120 60 01 75 300 Max Units VV VV mA kX kX mA X mA mA V MHz kHz mVrms dB dB % Electrical Characteristics TA e 25 C Parameter Voltage Gain Conditions Open Loop (Differential Input) f e 100 Hz Open Loop (Single Ended) f e 100 Hz Supply Current Input Resistance (Positive Input) (Negative Input) Input Current (Negative Input) Output Resistance Output Current VCC 9V to 40V RL e % Output Voltage Swing Unity Gain Bandwidth Power Bandwidth Maximum Input Voltage Supply Rejection Ratio Channel Separation Total Harmonic Distortion Total Equivalent Input Noise LM381A LM381 Peak-to-Peak Note 1 For operation in ambient temperatures above 25 C the device must be derated based on a 150 C maximum junction temperature and a thermal resistance of 80 C W junction to ambient Connection Diagram Dual-In-Line Package TL H 7841 – 2 Top View Order Number LM381N or LM381AN See NS Package Number N14A 2 Typical Applications Typical Tape Playback Amplifier Typical Magnetic Phono Preamp TL H 7841 – 3 Two-Pole Fast Turn-On NAB Tape Preamp Audio Mixer TL H 7841 – 4 TL H 7841 – 5 TL H 7841 – 6 Ultra-Low Distortion Amplifier (AV e 10 THD k 0 05% VOUT e 3 VRMS) TL H 7841 – 7 3 Typical Performance Characteristics Large Signal Frequency Response VCC vs ICC P-P Output Voltage VCC Swing vs % Distortion Channel Separation PSRR vs Frequency Gain and Phase Response Noise Voltage vs Frequency Noise Current vs Frequency Pulse Response TL H 7841 – 8 4 5 LM381 LM381A Low Noise Dual Preamplifier Physical Dimensions inches (millimeters) Molded Dual-In-Line Package (N) Order Number LM381N or LM381AN NS Package Number N14A 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 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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