March 1987
LM387/LM387A Low Noise Dual Preamplifier
General Description
Features
Y
Low noise
1.0 mV total input noise
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),
Y
High gain
104 dB open loop
Y
Single supply operation
Y
Wide supply range LM387
LM387A
9 to 30V
9 to 40V
110 dB
Y
Power supply rejection
b
large output voltage swing (V
CC
2V)p-p, and wide power
Y
b
Large output voltage swing (V
2V)p-p
CC
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.
Y
Wide bandwidth 15 MHz unity gain
Power bandwidth 75 kHz, 20 Vp-p
Internally compensated
Y
Y
Y
Y
Short circuit protected
Performance similar to LM381
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.
Schematic and Connection Diagrams
Dual-In-Line Package
TL/H/7845–2
Top View
Order Number LM387N or LM387AN
See NS Package Number N08E
TL/H/7845–1
Typical Applications
TL/H/7845–3
TL/H/7845–4
e
FIGURE 1. Flat Gain Circuit (A
1000)
V
FIGURE 2. NAB Tape Circuit
C
1995 National Semiconductor Corporation
TL/H/7845
RRD-B30M115/Printed in U. S. A.