NSC LM387N, LM387AN Datasheet

LM387/LM387A Low Noise Dual Preamplifier

LM387/LM387A Low Noise Dual Preamplifier

March 1987

General Description

The LM387 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 an internal power supply decoupler-regulator, pro­viding 110 dB supply rejection and 60 dB channel separa­tion. Other outstanding features include high gain (104 dB),
large output voltage swing (V
bandwidth (75 kHz, 20 Vp-p). The LM387A is a selected

b

2V)p-p, and wide power

CC

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 dual­in-line package. The LM387, LM387A is biased like the
LM381. See AN-64 and AN-104.

Schematic and Connection Diagrams

Features

Y

Low noise 1.0 mV total input noise

Y

High gain 104 dB open loop

Y

Single supply operation

Y

Wide supply range LM387 9 to 30V

Y

Power supply rejection 110 dB

Y

Large output voltage swing (V

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

LM387A 9 to 40V

b

2V)p-p

CC

Dual-In-Line Package

Top View

TL/H/7845– 2

Order Number LM387N or LM387AN

See NS Package Number N08E

TL/H/7845– 1

Typical Applications

TL/H/7845– 3

FIGURE 1. Flat Gain Circuit (A

C

1995 National Semiconductor Corporation RRD-B30M115/Printed in U. S. A.

TL/H/7845

e

1000)

V

FIGURE 2. NAB Tape Circuit

TL/H/7845– 4

Absolute Maximum Ratings

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales
Office/Distributors for availability and specifications.

Supply Voltage

LM387
LM387A

a

30V

a

40V

Power Dissipation (Note 1) 1.5W

Operating Temperature Range 0

Storage Temperature Range

Ctoa70§C

§

b

65§Ctoa150§C

Lead Temperature (Soldering, 10 sec.) 260§C

Electrical Characteristics T

e

25§C, V

A

e

14V, unless otherwise stated

CC

Parameter Conditions Min Typ Max Units

Voltage Gain Open Loop, fe100 Hz 160,000 V/V

Supply Current LM387, VCC9V–30V, R

Input Resistance

Positive Input 50 100 kX
Negative Input 200 kX

Input Current

Negative Input

LM387A, V

9V–40V, R

CC

L

e %

e %

L

10 mA
10 mA

0.5 3.1 mA

Output Resistance Open Loop 150 X

Output Current Source 8 mA

Output Voltage Swing Peak-to-Peak V

Sink 2 mA

b

2V

CC

Unity Gain Bandwidth 15 MHz

Large Signal Frequency 20 Vp-p (V
Response THD

l

24V),

CC

s

1%

75 kHz

Maximum Input Voltage Linear Operation 300 mVrms

Supply Rejection Ratio fe1 kHz

Input Referred

110 dB

Channel Separation fe1 kHz 40 60 dB

Total Harmonic Distortion 60 dB Gain, fe1 kHz 0.1 0.5 %

Total Equivalent Input 10 Hz – 10,000 Hz

Noise (Flat Gain Cricuit) LM387

Output Noise NAB Tape Unweighted

Playback Circuit Gain of 37 dB LM387A

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

C/W junction to ambient.

of 80

§

Figure 1

Figure 2

1.0 1.2 mVrms

400 700 mVrms

Typical Applications (Continued)

Two-Pole Fast Turn-ON NAB Tape Preamplifier

Frequency Response of NAB

Circuit of Figure 2

TL/H/7845– 5

TL/H/7845– 6

2