MAX9744

XX-XXXX; Rev 0; 3/08 20W Stereo Class D Speaker Amplifier with Volume Control General Description The MAX9744 20W stereo Class D audio power amplifier provides Class AB amplifier performance with Class D efficiency, conserving board space and eliminating the need for a bulky heatsink. This device features single-supply operation, adjustable gain, shutdown mode, SYNC output, speaker mute, and industry-leading clickand-pop suppression. The MAX9744 features a 64-step dual-mode (analog or digital), programmable volume control and mute function. The MAX9744 operates from a 4.5V to 14V single supply and can deliver up to 20W per channel into a 4Ω speaker with a 14V supply. The MAX9744 offers two modulation schemes: a fixedfrequency modulation mode that allows one of several preset switching frequencies to be selected, and a spread-spectrum modulation mode that helps to reduce EMI-radiated emissions. The MAX9744 features high 75dB PSRR, low 0.04% THD+N, and SNR in excess of 90dB. Robust short-circuit and thermal-overload protection prevent device damage during a fault condition. The MAX9744 is available in a 44-pin thin QFN-EP (7mm x 7mm x 0.8mm) package and is specified over the extended -40°C to +85°C temperature range. Features ♦ Wide 4.5V to 14V Power-Supply Voltage Range ♦ Filterless Spread-Spectrum Modulation Lowers Radiated RF Emissions from Speaker Cables ♦ Integrated Volume Control (I2C or Analog) ♦ Low 0.04% THD+N ♦ High 75dB PSRR MAX9744 ♦ High 93% Efficiency (20W, 8Ω) ♦ Low-Power Shutdown Mode ♦ Integrated Click-and-Pop Suppression ♦ Short-Circuit and Thermal-Overload Protection ♦ Available in a 44-Pin Thin QFN-EP (7mm x 7mm x 0.8mm) IN PART MAX9744ETH+ CLASS D MODULATOR OUTPUT MAGNITUDE (dBV) CLASS D MODULATOR SYNCOUT A R TEMP RANGE -40°C to +85°C 40 35 30 25 20 15 10 5 0 30 60 80 100 120 Ordering Information PINPACKAGE 44 TQFN-EP* PKG CODE T4477-3 M Applications 4.5V TO 14V VOLUME CONTROL OSCILLATOR +Denotes a lead-free package. Flat-Panel Televisions PC Speaker Systems Multimedia Docking Stations *EP = Exposed paddle. Pin Configuration appears at end of data sheet. E LI 3V TO 3.6V Simplified Block Diagram MAX9744 R MAX9744 EMI WITH FERRITE BEAD FILTERS (VDD = 12V, 1m CABLE, 8Ω LOAD) BIAS P MUTE SHUTDOWN CONTROL I2C ANALOG CONTROL SYNC ________________________________________________________________ Maxim Integrated Products Y OVER 20dB MARGIN TO EN55022 B LIMIT ♦ 20W Stereo Output (4Ω, VDD = 12V, THD+N = 10%) 160 200 240 280 140 180 220 260 300 FREQUENCY (MHz) 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.