TLH7845

March 1987

LM387LM387A Low Noise Dual Preamplifier

General Description

The LM387 is a dual preamplifier for the amplification of low

level signals in applications requiring optimum noise per-

formance Each of the two amplifiers is completely indepen-

dent with an internal power supply decoupler-regulator pro-

viding 110 dB supply rejection and 60 dB channel separa-

tion Other outstanding features include high gain (104 dB)

bandwidth (75 kHz 20 Vp-p) The LM387A is a selected

version of the LM387 that has lower noise in a NAB tape

circuit and can operate on a larger supply voltage The

LM387 operates from a single supply across the wide range

of 9V to 30V the LM387A operates on a supply of 9V to

40V

The amplifiers are internally compensated for gains greater

than 10 The LN387 LM387A is available in an 8-lead dual-

in-line package The LM387 LM387A is biased like the

LM381 See AN-64 and AN-104

Features

Y

Low noise

10 mV total input noise

Y

High gain

104 dB open loop

Y

Single supply operation

Y

Wide supply range LM387

9 to 30V

LM387A

9 to 40V

Y

Power supply rejection

110 dB

Y

Y

Wide bandwidth 15 MHz unity gain

Y

Power bandwidth 75 kHz 20 Vp-p

Y

Internally compensated

Y

Short circuit protected

Y

Performance similar to LM381

Schematic and Connection Diagrams

TLH7845 – 1

Dual-In-Line Package

TLH7845 – 2

Top View

Order Number LM387N or LM387AN

See NS Package Number N08E

Typical Applications

TLH7845 – 3

TLH7845 – 4

FIGURE 2 NAB Tape Circuit

C1995 National Semiconductor Corporation

RRD-B30M115Printed in U S A