MAXIM MAX9708 20W 40W, Filterless, Spread-Spectrum, MonoStereo, Class-D Amplifier Data Sheet User Manual

19-3678; Rev 2; 3/06

EVALUATION KIT AVAILABLE

20W/40W, Filterless, Spread-Spectrum,

Mono/Stereo, Class D Amplifier General Description Features

The MAX9708 mono/stereo, Class D audio power amplifi- 2 x 21W Output Power in Stereo Mode er delivers up to 2 x 21W into an 8Ω stereo mode and (8Ω, THD = 10%) 1 x 42W into a 4Ω load in mono mode while offering up to

1 x 42W Output Power in Mono Mode

87% efficiency. The MAX9708 provides Class AB amplifi-

(4Ω, THD = 10%)

er performance with the benefits of Class D efficiency,

High Efficiency: Up to 87%

eliminating the need for a bulky heatsink and conserving

power. The MAX9708 operates from a single +10V to Filterless Class D Amplifier

+18V supply, driving the load in a BTL configuration. Unique Patented Spread-Spectrum Mode

The MAX9708 offers two modulation schemes: a fixed- Programmable Gain (+22d B, +25d B, +29.5d B, frequency modulation (FFM) mode, and a spread-spec- +36d B)

trum modulation (SSM) mode that reduces

High PSRR (90d B at 1k Hz)

EMI-radiated emissions. The MAX9708 can be synchro-

Differential Inputs Suppress Common-Mode

nized to an external clock from 600k Hz to 1.2MHz. A

Noise

synchronized output allows multiple units to be cascad-

Shutdown and Mute Control

ed in the system.

Integrated Click-and-Pop Suppression

Features include fully differential inputs, comprehensive

click-and-pop suppression, and four selectable-gain set- Low 0.1% THD+N

tings (22d B, 25d B, 29.5d B, and 36d B). A pin-program- Current Limit and Thermal Protection mable thermal flag provides seven different thermal

Programmable Thermal Flag

warning thresholds. Short-circuit and thermal-overload

SYNC Input/Output

protection prevent the device from being damaged

during a fault condition. Available in Thermally Efficient, Space-Saving Packages: 56-Pin TQFN and 64-Pin TQFP

The MAX9708 is available in 56-pin TQFN (8mm x 8mm x 0.8mm) and 64-pin TQFP (10mm x 10mm x 1.4mm)

Ordering Information

packages, and is specif ied over the extended -40°C to +85°C temperature range.

PART TEMP RANGE PIN-PACKAGE

Applications

MAX9708ETN+ -40°C to +85°C 56 TQFN-EP** T5688-3

LCD TVs PDP TVs

MAX9708ECB* -40°C to +85°C 64 TQFP-EP** C64E-6

Automotive PC/Hi Fi Audio Solutions

+Denotes lead-free package. *Future product—Contact factory for availability. **EP = Exposed paddle.Pin Configurations appear at end of data sheet.

Simplified Block Diagram

MAX9708 SYNCOUT SYNCOUT

FS1, FS2 FS1, FS2 MAX9708

SYNC SYNC

CHANNEL

AUDIO

CLASS D CLASS D

INPUT

MODULATOR MODULATOR

CHANNEL

GAIN VDIGITAL

OUTPUT GAIN

OUTPUT

CONTROL

MONO PROTECTION CONTROL

PROTECTION

G1, G2 G1, G2 TH0, TH1, TH0, TH1,

TH2 TEMP

TH2 TEMP

STEREO MODE MONO MODE

Maxim Integrated Products

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.