LM387 LM387A Low Noise Dual Preamplifier
March 1987
LM387 LM387A 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)
large output voltage swing (V
CC
b
2V)p-p and wide power
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
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Low noise
1 0
mV
total input noise
High gain
104 dB open loop
Single supply operation
Wide supply range LM387
9 to 30V
LM387A
9 to 40V
Power supply rejection
110 dB
Large output voltage swing (V
CC
b
2V)p-p
Wide bandwidth 15 MHz unity gain
Power bandwidth 75 kHz 20 Vp-p
Internally compensated
Short circuit protected
Performance similar to LM381
Schematic and Connection Diagrams
Dual-In-Line Package
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Top View
Order Number LM387N or LM387AN
See NS Package Number N08E
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Typical Applications
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FIGURE 1 Flat Gain Circuit (A
V
e
1000)
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FIGURE 2 NAB Tape Circuit
C
1995 National Semiconductor Corporation
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RRD-B30M115 Printed in U S A
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