LM4953

Ground-Referenced, Ultra Low Noise, Ceramic Speaker

Driver

General Description

The LM4953 is an audio power amplifier designed for driving

Ceramic Speaker in portable applications. When powered by

a 3.6V supply, it is capable of forcing 12.6Vpp across a 2µF

+30

Ω bridge-tied-load (BTL) with less than 1% THD+N.

Boomer audio power amplifiers were designed specifically to

provide high quality output power with a minimal amount of

external components. The LM4953 does not require boot-

strap capacitors, or snubber circuits. Therefore it is ideally

suited for display applications requiring high power and mini-

mal size.

The LM4953 features a low-power consumption shutdown

mode. Additionally, the LM4953 features an internal thermal

shutdown protection mechanism.

The LM4953 contains advanced pop & click circuitry that

eliminates noises which would otherwise occur during

turn-on and turn-off transitions.

The LM4953 is unity-gain stable and can be configured by

external gain-setting resistors.

Key Specifications

(2µF+30

Ω load, 1% THD+N,

V

12.6V

1µA (max)

Features

n

Pop & click circuitry eliminates noise during turn-on and

turn-off transitions

n

Low, 1µA (max) shutdown current

n

Low, 7mA (typ) quiescent current

n

12.6Vpp mono BTL output, load = 2µF+ 30

Ω

n

Thermal shutdown

n

Unity-gain stable

n

External gain configuration capability

Applications

n

Cellphone

n

PDA

Typical Application

20142168

FIGURE 1. Typical Application Circuit

September 2005

© 2005 National Semiconductor Corporation

DS201421

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