LM4665

www.ti.com

SNAS146E – FEBRUARY 2002 – REVISED MAY 2013

LM4665

Filterless High Efficiency 1W Switching Audio

Amplifier

Check for Samples: LM4665

1

FEATURES

DESCRIPTION

The LM4665 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 (2V/V) or 12dB (4V/V)

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

•

User Selectable Shutdown High or Low Logic

LM4665 processes analog inputs with a delta-sigma

Level

modulation technique that lowers output noise and

•

Minimum External Components

THD when compared to conventional pulse width

•

"Click and Pop" Suppression Circuitry

modulators.

•

Micro-Power Shutdown Mode

The LM4665 is designed to meet the demands of

mobile phones and other portable communication

•

Short Circuit Protection

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

•

DSBGA, WSON, and VSSOP Packages (No

capable

of

driving

8

Ω

transducer

loads

at

a

Heat Sink Required)

continuous average output of 400mW with less than

2%THD+N.

APPLICATIONS

The

LM4665

has

high

efficiency

with

an

8

Ω

•

Mobile Phones

transducer load compared to a typical Class AB

•

PDAs

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

100mW power level is 75%, reaching 80% at 400mW

•

Portable Electronic Devices

output power.

KEY SPECIFICATIONS

The LM4665 features a low-power consumption

shutdown mode. Shutdown may be enabled by either

•

Efficiency at 100mW into 8

Ω Transducer

a logic high or low depending on the mode selection.

75%(typ)

•

Efficiency at 400mW into 8

Ω Transducer

(high) or GND (low) enables the Shutdown pin to be

80%(typ)

driven in a likewise manner to activate shutdown.

•

Total Quiescent Power Supply Current (3V)

The LM4665 has fixed selectable gain of either 6dB

3mA(typ)

or 12dB. The LM4665 has short circuit protection

•

Total Shutdown Power Supply Current (3V)

across the outputs.

0.01µA(typ)

•

Single Supply Range (VSSOP & WSON) 2.7V to

5.5V

•

Single Supply Range (DSBGA) (Note 11) 2.7V

to 3.8V

1

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

All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2002–2013, 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.