LM4670

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SNAS240C – DECEMBER 2004 – REVISED MAY 2013

LM4670 Boomer™ Audio Power Amplifier Series Filterless High Efficiency 3W Switching

Audio Amplifier

Check for Samples: LM4670

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FEATURES

DESCRIPTION

The LM4670 is a fully integrated single-supply high

23

•

No Output Filter Required for Inductive Loads

efficiency switching audio amplifier. It features an

•

Externally Configurable Gain

innovative modulator that eliminates the LC output

•

Very Fast Turn on Time: 1.35ms (Typ)

filter

used

with

typical

switching

amplifiers.

Eliminating

the

output

filter

reduces

external

•

Minimum External Components

component

count,

simplifies

circuit

design,

and

•

"Click and Pop" Suppression Circuitry

reduces board area. The LM4670 processes analog

•

Micro-Power Shutdown Mode

inputs with a delta-sigma modulation technique that

lowers output noise and THD when compared to

•

Short Circuit Protection

conventional pulse width modulators.

•

Available in Space-Saving DSBGA and WSON

Packages

The LM4670 is designed to meet the demands of

mobile phones and other portable communication

devices. Operating on a single 5V supply, it is

APPLICATIONS

capable of driving a 4

Ω speaker load at a continuous

•

Mobile Phones

average output of 2.3W with less than 1% THD+N. Its

•

PDAs

flexible power supply requirements allow operation

from 2.4V to 5.5V.

•

Portable Electronic Devices

The LM4670 has high efficiency with speaker loads

KEY SPECIFICATIONS

compared to a typical Class AB amplifier. With a 3.6V

supply driving an 8

Ω speaker, the IC's efficiency for a

•

Efficiency at 3.6V, 100mW into 8

Ω Speaker,

100mW power level is 77%, reaching 88% at 600mW

77% (Typ)

output power.

•

Efficiency at 3.6V, 600mW into 8

Ω Speaker,

The LM4670 features a low-power consumption

88% (Typ)

shutdown mode. Shutdown may be enabled by

•

Efficiency at 5V, 1W into 8

Ω Speaker, 87%

driving the Shutdown pin to a logic low (GND).

(Typ)

The gain of the LM4670 is externally configurable

•

Quiescent Current, 3.6V Supply, 4.8mA (Typ)

which allows independent gain control from multiple

•

Total Shutdown Power Supply Current, 0.01µA

sources by summing the signals.

(Typ)

•

Single Supply Range, 2.4 to 5.5V

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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

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

2

Boomer is a trademark of Texas Instruments.

3

All other 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.