LM4991

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SNAS217A – MAY 2004 – REVISED APRIL 2013

LM4991

3W Audio Power Amplifier with Shutdown Mode

Check for Samples: LM4991

1

FEATURES

DESCRIPTION

The LM4991 is a mono bridged audio power amplifier

2

•

Available in Space-Saving WSON and SOIC

capable of delivering 3W of continuous average

Packages

power into a 3

Ω load with less than 10% THD when

•

Ultra Low Current Shutdown Mode

powered by a 5V power supply (see Note below). To

•

Can Drive Capacitive Loads up to 500pF

conserve

power

in

portable

applications,

the

LM4991's micropower shutdown mode (ISD = 0.1µA,

•

Improved Click and Pop Circuitry Reduces

typ) is activated when VDD is applied to the

Noises During Turn-On and Turn-Off

SHUTDOWN pin.

Transitions

Boomer

audio

power

amplifiers

are

designed

•

2.2 - 5.5V Operation

specifically to provide high power, high fidelity audio

•

No Output Coupling Capacitors, Snubber

output. They require few external components and

Networks, Bootstrap Capacitors or Gain-

operate on low supply voltages from 2.2V to 5.5V.

Setting Resistors Required

Since the LM4991 does not require output coupling

capacitors,

bootstrap

capacitors,

or

snubber

•

Unity-Gain Stable

networks, it is ideally suited for low-power portable

systems that require minimum volume and weight.

APPLICATIONS

Additional LM4991 features include thermal shutdown

•

Wireless and Cellular Handsets

protection, unity-gain stability, and external gain set.

•

PDAs

Note: An LM4991LD that has been properly mounted

•

Portable Computers

to a circuit board will deliver 3W into 3

Ω (at 10%

•

Desktop Computers

THD). The other package options for the LM4991 will

deliver 1.5W into 8

Ω (at 10% THD). See the

KEY SPECIFICATIONS

Application

Information

sections

for

further

information

concerning

the

LM4991LD

and

•

Improved PSRR at 217kHz and 1kHz: 64 dB

LM4991M.

(typ)

•

PO at VDD = 5.0V, 10% THD, 1kHz

–

LM4991LD (only), 3

Ω, 4Ω: 3W (typ), 2.5 W

(typ)

–

All packages, 8

Ω load: 1.5 W (typ)

•

Shutdown current: 0.1µA (typ)

Connection Diagrams

Top View

Top View

Figure 1. SOIC Package

Figure 2. WSON Package

See Package Number D0008A

See Package Number NGN0008A

1

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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2004–2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.