Datasheet LM384N Datasheet (NSC)

LM384
5W Audio Power Amplifier

General Description

The LM384 is a power audio amplifier for consumer applica­tion. In order to holdsystemcostto a minimum, gain is inter­nally fixed at 34 dB. A unique input stage allows inputs to be
ground referenced. The output is automatically
self-centering to one half the supply voltage.

The output is short-circuit proof with internal thermal limiting.
The package outline is standard dual-in-line. A copper lead
frame is used with the center three pins on either side com­prising a heat sink. This makes the device easy to use in
standard p-c layout.

Uses include simple phonograph amplifiers, intercoms, line
drivers, teaching machine outputs, alarms, ultrasonic driv­ers, TV sound systems, AM-FM radio, sound projector sys­tems, etc. See AN-69 for circuit details.

Features

n Wide supply voltage range
n Low quiescent power drain
n Voltage gain fixed at 50
n High peak current capability
n Input referenced to GND
n High input impedance
n Low distortion
n Quiescent output voltage is at one half of the supply

voltage

n Standard dual-in-line package

Schematic Diagram

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February 1995

LM384 5W Audio Power Amplifier

© 1999 National Semiconductor Corporation DS007843 www.national.com

Absolute Maximum Ratings (Note 1)

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

Supply Voltage 28V
Peak Current 1.3A
Power Dissipation (See (Notes 4, 5)) 1.67W
Input Voltage

±

0.5V

Storage Temperature −65˚C to +150˚C

Operating Temperature 0˚C to +70˚C
Lead Temperature

(Soldering, 10 sec.) 260˚C

Thermal Resistance

θ

JC

30˚C/W

θ

JA

79˚C/W

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to
the device may occur. Operating Ratings indicate conditions for which the de­vice is functional, but do not guarantee specific performance limits.

Electrical Characteristics (Note 2)

Symbol Parameter Conditions Min Typ Max Units

Z

IN

Input Resistance 150 kΩ

I

BIAS

Bias Current Inputs Floating 100 nA

A

V

Gain 40 50 60 V/V

P

OUT

Output Power THD=10%,R

L

=

8Ω 5 5.5 W

I

Q

Quiescent Supply Current 8.5 25 mA

V

OUT Q

Quiescent Output Voltage 11 V

BW Bandwidth P

OUT

=

2W, R

L

=

8Ω 450 kHz

V

+

Supply Voltage 12 26 V

I

SC

Short Circuit Current (Note 6) 1.3 A

PSRR

RTO

Power Supply Rejection Ratio 31 dB
(Note 3) )

THD Total Harmonic Distortion P

OUT

=

4W, R

L

=

8Ω 0.25 1.0

%

Note 2: V

+

=

22V and T

A

=

25˚C operating with a Staver V7 heat sink for 30 seconds.

Note 3: Rejection ratio referred to the output with C

BYPASS

=

5 µF, freq=120 Hz.

Note 4: The maximum junction temperature of the LM384 is 150˚C.
Note 5: The package is to be derated at 15˚C/W junction to heat sink pins.
Note 6: Output is fully protected against a shorted speaker condition at all voltages up to 22V.

Heat Sink Dimensions

Staver “V7” Heat Sink

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Staver Company
41 Saxon Ave.
P.O. Drawer H
Bay Shore, N.Y.
Tel: [phone]

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Typical Performance Characteristics

Device Dissipation vs
Ambient Temperature

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Thermal Resistance vs
Square Inches

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Supply Decoupling vs
Frequency

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Total Harmonic Distortion
vs Output Power

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Output Voltage Gain vs
Frequency

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Total Harmonic Distortion
vs Frequency

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Power Supply Current vs
Supply Voltage

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Device Dissipation vs
Output Power — 16Ω Load

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Device Dissipation vs
Output Power — 8Ω Load

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Typical Performance Characteristics (Continued)

Block and Connection Diagrams

Device Dissipation vs
Output Power — 4Ω Load

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Dual-In-Line Package

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Note 7: Heatsink Pins

Top View

Order Number LM384N

See NS Package Number N14A

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Typical Applications

Typical 5W Amplifier

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Bridge Amplifier

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Intercom

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*For stability with high current loads

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Typical Applications (Continued)

Phase Shift Oscillator

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Physical Dimensions inches (millimeters) unless otherwise noted

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DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL
COUNSEL 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 properly used in
accordance with instructions for use provided in the
labeling, can be reasonably expected to result in a
significant injury to the user.

2. A critical component is any component of a life
support device or system whose failure to perform
can be reasonably expected to cause the failure of
the life support device or system, or to affect its
safety or effectiveness.

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Molded Dual-In-Line Package (N)

Order Number LM384N

NS Package Number N14A

LM384 5W Audio Power Amplifier

National does not assume any responsibility for use of 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.