MAX9744 19-4078 Rev 1 9/08 20W Stereo Class D Speaker Amplifier with Volume Control General Description Features The MAX9744 20W stereo Class D audio power amplifi- Wide 4.5V to 14V Power-Supply Voltage Range er provides Class AB amplifier performance with Class Filterless Spread-Spectrum Modulation Lowers D efficiency, conserving board space and eliminating Radiated RF Emissions from Speaker Cables the need for a bulky heatsink. This device features sin- gle-supply operation, adjustable gain, shutdown mode, 20W Stereo Output (4 , V = 12V, THD+N = 10%) DD a SYNC output, speaker mute, and industry-leading 2 Integrated Volume Control (I C or Analog) click-and-pop suppression. Low 0.04% THD+N The MAX9744 features a 64-step dual-mode (analog or digital), programmable volume control and mute func- High 75dB PSRR tion. The MAX9744 operates from a 4.5V to 14V single High 93% Efficiency supply and can deliver up to 20W per channel into a 4 speaker with a 14V supply. Integrated Click-and-Pop Suppression The MAX9744 offers two modulation schemes: a fixed- Low-Power Shutdown Mode frequency modulation mode that allows one of several Short-Circuit and Thermal-Overload Protection preset switching frequencies to be selected, and a spread-spectrum modulation mode that helps to Available in a 44-Pin Thin QFN-EP (7mm x 7mm x reduce EMI-radiated emissions. 0.8mm) The MAX9744 features high 75dB PSRR, low 0.04% THD+N, and SNR in excess of 90dB. Robust short-cir- Ordering Information cuit and thermal-overload protection prevent device damage during a fault condition. The MAX9744 is avail- PART TEMP RANGE PIN-PACKAGE able in a 44-pin thin QFN-EP (7mm x 7mm x 0.8mm) MAX9744ETH+ -40C to +85C 44 TQFN-EP* package and is specified over the extended -40C to +85C temperature range. +Denotes a lead-free/RoHS-compliant package. Applications *EP = Exposed pad. Flat-Panel Televisions PC Speaker Systems Multimedia Docking Stations Pin Configuration appears at end of data sheet. Simplified Block Diagram 3V TO 3.6V 4.5V TO 14V MAX9744 EMI WITH FERRITE BEAD FILTERS MAX9744 (V = 12V, 1m CABLE, 8 LOAD) DD 40 35 VOLUME EN5022 B LIMIT BIAS CONTROL 30 25 20 MUTE SHUTDOWN 15 CONTROL 2 I C 10 ANALOG 5 CONTROL SYNC SYNCOUT 30 60 100 140 180 220 260 300 OSCILLATOR 80 120 160 240 280 200 FREQUENCY (MHz) Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLE CLASS D CLASS D MODULATOR MODULATOR OUTPUT MAGNITUDE (dBV)20W Stereo Class D Speaker Amplifier with Volume Control ABSOLUTE MAXIMUM RATINGS PVDD to PGND ....................................................................+16V 44-Pin Thin QFN (derate 37mW/C above +70C, V to GND ...........................................................................+4V multilayer board) ......................................................2963mW DD FB , SYNCOUT, SYNC, SDA/VOL, ADDR1, , Single-Layer Board................................................37C/W JA ADDR2 to GND........................................-0.3V to (V + 0.3V) , Multilayer Board .................................................27C/W JA DD BOOT to V ..........................................................-0.3V to +6V Continuous Input Current (PVDD, PGND).............................6.4A DD BOOT to OUT ........................................................-0.3V to +6V Continuous Output Current (OUT ) ......................................3.2A OUT to GND ..........................................-0.3V to (PVDD + 0.3V) Continuous Input Current (except OUT ).........................20mA PGND to GND .......................................................-0.3V to +0.3V Junction Temperature......................................................+150C Any Other Pin to GND ..............................................-0.3V to +4V Operating Temperature Range ...........................-40C to +85C OUT , Short-Circuit Duration......................................Continuous Storage Temperature Range .............................-65C to +150C Continuous Power Dissipation (T = +70C) Lead Temperature (soldering, 10s) .................................+300C A 44-Pin Thin QFN (derate 27mW/C above +70C, single-layer board)...................................................2162mW Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V = 12V, V = 3.3V, V = V = 0V, V = 0V max volume setting all speaker load resistors connected between PVDD DD GND PGND MUTE OUT + and OUT -, R = , unless otherwise stated, C = 0.1F, C = 2.2F, C = 0.47F, R = 20k, R = 20k, spread- L BOOT BIAS IN IN F spectrum mode, filterless modulation mode, see the Functional Diagrams/Typical Application Circuits. T = T to T , unless oth- A MIN MAX erwise noted. Typical values are at T = +25C.) (Note 1) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS GENERAL Speaker Amplifier Supply Voltage PVDD Inferred from PSRR test 4.5 14 V Range Supply Voltage Range V Inferred from PSRR test 2.7 3.6 V DD I 20 35 DD Quiescent Current mA I 10 20 PVDD I T = +25C 0.1 1 VDDSHDN A Shutdown Current A I T = +25C 0.1 1 PVDDSHDN A Turn-On Time t 200 ms ON Common-Mode Bias Voltage V 1.5 V BIAS Input Amplifier Output-Voltage Specified as V V , R = 2k DD OH L V 20 mV OH Swing High connected to 1.5V Input Amplifier Output-Voltage Specified as V GND, R = 2k OL L V 20 mV OL Swing Low connected to 1.5V Input Amplifier Output Short- 60 mA Circuit Current Limit Input Amplifier Gain-Bandwidth GBW 1.8 MHz Product SPEAKER AMPLIFIERS Output stage gain 29.5 Maximum Gain A dB VMAX volume setting Total gain (Note 2) 29.5 Output Offset V T = 25C 2 15 mV OS A 2 MAX9744