LM4667, LM4667MMBD

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SNAS165C – SEPTEMBER 2003 – REVISED MAY 2013

LM4667

Filterless High Efficiency 1.3W Switching Audio

Amplifier

Check for Samples: LM4667, LM4667MMBD

1

FEATURES

DESCRIPTION

The LM4667 is a fully integrated single-supply high

2

•

No Output Filter Required for Inductive

efficiency switching audio amplifier. It features an

Transducers

innovative modulator that eliminates the LC output

•

Selectable Gain of 6dB or 12dB

filter

used

with

typical

switching

amplifiers.

•

Very Fast Turn on Time: 5ms (typ)

Eliminating the output filter reduces parts count,

simplifies circuit design, and reduces board area. The

•

Minimum External Components

LM4667 processes analog inputs with a delta-sigma

•

"Click and Pop" Suppression Circuitry

modulation technique that lowers output noise and

•

Micro-Power Shutdown Mode

THD when compared to conventional pulse width

modulators.

•

Short Circuit Protection

•

Space-Saving DSBGA and VSSOP Packages

The LM4667 is designed to meet the demands of

mobile phones and other portable communication

devices. Operating on a single 3V supply, it is

KEY SPECIFICATIONS

capable

of

driving

8

Ω

transducer

loads

at

a

•

Efficiency at 3V, 100mW into 8

Ω Transducer

continuous average output of 450mW with less than

74% (typ)

1%THD+N. Its flexible power supply requirements

allow operation from 2.7V to 5.5V.

•

Efficiency at 3V, 450mW into 8

Ω Transducer

84% (typ)

The

LM4667

has

high

efficiency

with

an

8

Ω

•

Efficiency at 5V, 1W into 8

Ω Transducer 86%

transducer load compared to a typical Class AB

(typ)

amplifier. With a 3V supply, the IC's efficiency for a

100mW power level is 74%, reaching 84% at 450mW

•

Total Quiescent Power Supply Current: 3.5mA

output power.

(typ)

The LM4667 features a low-power consumption

•

Total Shutdown Power Supply Current: 0.01

μA

shutdown mode. Shutdown may be enabled by

(typ)

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

•

Single Supply Range: 2.7V to 5.5V

The LM4667 has fixed selectable gain of either 6dB

or 12dB. The LM4667 has short circuit protection

APPLICATIONS

•

Mobile Phones

across the outputs.

•

PDAs

•

Portable Electronic Devices

1

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2

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PRODUCTION DATA information is current as of publication date.

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Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

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