LM4675, LM4675SDBD, LM4675TLBD

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SNAS353C – AUGUST 2006 – REVISED MAY 2013

LM4675

Ultra-Low EMI, Filterless, 2.65W, Mono, Class D

Audio Power Amplifier with Spread Spectrum

Check for Samples: LM4675, LM4675SDBD, LM4675TLBD

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FEATURES

DESCRIPTION

The LM4675 is a single supply, high efficiency,

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•

Spread Spectrum Architecture Reduces EMI

2.65W, mono, Class D audio amplifier. A spread

•

Mono Class D Operation

spectrum, filterless PWM architecture reduces EMI

•

No Output Filter Required for Inductive Loads

and eliminates the output filter, reducing external

component count, board area consumption, system

•

Externally Configurable Gain

cost, and simplifying design.

•

Very Fast Turn On Time: 17

μs (typ)

The LM4675 is designed to meet the demands of

•

Minimum External Components

mobile phones and other portable communication

•

"Click and Pop" Suppression Circuitry

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

•

Micro-Power Shutdown Mode

capable of driving a 4

Ω speaker load at a continuous

average output of 2.2W with less than 1% THD+N. Its

•

Available in Space-Saving 0.5mm Pitch

flexible power supply requirements allow operation

DSBGA and WSON Packages

from 2.4V to 5.5V. The wide band spread spectrum

architecture of the LM4675 reduces EMI-radiated

APPLICATIONS

emissions due to the modulator frequency.

•

Mobile Phones

The LM4675 has high efficiency with speaker loads

•

PDAs

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

•

Portable Electronic Devices

supply driving an 8

Ω speaker, the IC's efficiency for a

100mW power level is 80%, reaching 89% at 400mW

output power.

KEY SPECIFICATIONS

The LM4675 features a low-power consumption

•

Efficiency at 3.6V, 400mW into 8

Ω Speaker:

shutdown mode. Shutdown may be enabled by

89% (typ)

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

•

Efficiency at 3.6V, 100mW into 8

Ω Speaker:

The gain of the LM4675 is externally configurable

80% (typ)

which allows independent gain control from multiple

•

Efficiency at 5V, 1W into 8

Ω Speaker: 89%

sources by summing the signals. Output short circuit

(typ)

and thermal overload protection prevent the device

•

Quiescent Current, 3.6V Supply: 2.2mA (typ)

from damage during fault conditions.

•

Total Shutdown Power Supply Current: 0.01µA

(typ)

•

Single Supply Range: 2.4V to 5.5V

•

PSRR, f = 217Hz: 82dB

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PRODUCTION DATA information is current as of publication date.

Copyright © 2006–2013, 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.