LM4960

Piezoelectric Speaker Driver

General Description

The LM4960 utilizes a switching regulator to drive a dual

audio power amplifier. It delivers 24V

ceramic speaker with less than 1.0% THD+N while operating

on a 3.0V power supply.

The LM4960’s switching regulator is a current-mode boost

converter operating at a fixed frequency of 1.6MHz.

Boomer audio power amplifiers were designed specifically to

provide high quality output power with a minimal amount of

external components. The LM4960 does not require output

coupling capacitors or bootstrap capacitors, and therefore is

ideally suited for mobile phone and other low voltage appli-

cations where minimal power consumption is a primary re-

quirement.

The LM4960 features a low-power consumption externally

controlled micropower shutdown mode. Additionally, the

LM4960 features and internal thermal shutdown protection

mechanism along with a short circuit protection.

The LM4960 is unity-gain stable and can be configured by

external gain-setting resistors.

Key Specifications

n

V

≤ 1%

24V

n

Power supply range

3.0 to 7V

n

Switching Frequency

1.6MHz (typ)

Features

n

Stereo BTL amplifier

n

Low current shutdown mode

n

"Click and pop" suppression circuitry

n

Low Quiescent current

n

Unity-gain stable audio amplifiers

n

External gain configuration capability

n

Thermal shutdown protection circuitry

n

Wide input voltage range (3.0V - 7V)

n

1.6MHz switching frequency

Applications

n

Mobile phone

n

PDA’s

Connection Diagram

LM4960SQ

20076582

Top View

Order Number LM4960SQ

See NS Package Number

October 2004

© 2004 National Semiconductor Corporation

DS200765

www.national.com