General Description

The MAX9700 mono class D audio power amplifier pro-

vides class AB amplifier performance with class D effi-

ciency, conserving board space and extending battery

life. Using a class D architecture, the MAX9700 delivers

1.2W into an 8

Ω load while offering efficiencies above

90%. A patented, low-EMI modulation scheme renders

the traditional class D output filter unnecessary.

The MAX9700 offers two modulation schemes: a fixed-

frequency (FFM) mode, and a spread-spectrum (SSM)

mode that reduces EMI-radiated emissions due to the

modulation frequency. Furthermore, the MAX9700 oscil-

lator can be synchronized to an external clock through

the SYNC input, allowing the switching frequency to be

user defined. The SYNC input also allows multiple

MAX9700s to be cascaded and frequency locked, mini-

mizing interference due to clock intermodulation. The

device utilizes a fully differential architecture, a full-

bridged output, and comprehensive click-and-pop sup-

pression. The gain of the MAX9700 is set internally

(MAX9700A: 6dB, MAX9700B: 12dB, MAX9700C:

15.6dB, MAX9700D: 20dB), further reducing external

component count.

The MAX9700 features high 72dB PSRR, a low 0.01%

THD+N, and SNR in excess of 90dB. Short-circuit and

thermal-overload protection prevent the device from

damage during a fault condition. The MAX9700 is avail-

packages. The MAX9700 is specified over the extended

-40°C to +85°C temperature range.

Applications

Features

♦ Filterless Amplifier Passes FCC Radiated

Emissions Standards with 100mm of Cable

♦ Unique Spread-Spectrum Mode Offers 5dB

Emissions Improvement Over Conventional

Methods

♦ Optional External SYNC Input

♦ Simple Master-Slave Setup for Stereo Operation

♦ 94% Efficiency

♦ 1.2W into 8Ω

♦ Low 0.01% THD+N

♦ High PSRR (72dB at 217Hz)

♦ Integrated Click-and-Pop Suppression

♦ Low Quiescent Current (4mA)

♦ Low-Power Shutdown Mode (0.1µA)

♦ Short-Circuit and Thermal-Overload Protection

♦ Available in Thermally Efficient, Space-Saving

Packages

10-Pin µMAX

1.2W, Low-EMI, Filterless,

Class D Audio Amplifier

________________________________________________________________ Maxim Integrated Products

1

1

2

3

4

5

10

9

8

7

6

OUT-

OUT+

PGND

GND

IN-

IN+

MAX9700

TDFN/

µMAX

TOP VIEW

SYNC

SHDN

Pin Configurations

Ordering Information

MAX9700

DIFFERENTIAL

AUDIO INPUT

SYNC

INPUT

OSCILLATOR

MODULATOR

AND H-BRIDGE

Block Diagram

19-3030; Rev 1; 6/04

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Cellular Phones

PDAs

MP3 Players

Portable Audio

PART

TEMP RANGE

PIN-

PACKAGE

TOP

MARK

MAX9700AETB

-40

10 TDFN

ACM

MAX9700AEUB

-40

10 µMAX

—

MAX9700AEBC-T

-40

12 UCSP-12

—

MAX9700BETB

-40

10 TDFN

ACI

MAX9700BEUB

-40

10 µMAX

—

MAX9700BEBC-T

-40

12 UCSP-12

—

Pin Configurations continued at end of data sheet.

Ordering Information continued at end of data sheet.

UCSP is a trademark of Maxim Integrated Products, Inc.

Selector Guide appears at end of data sheet.