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The MAX9773 3rd-generaTIon, ultra-low EMI, stereo,Class D audio power amplifier provides Class AB performancewith Class D efficiency. The MAX9773 delivers1.8W per channel into a 4Ω load, and offersefficiencies above 90%. AcTIve emissions limiTIng (AEL)circuitry greatly reduces EMI by acTIvely controlling theoutput FET gate transitions under all possible transientconditions. AEL controls high-frequency emissionsresulting from conventional Class D free-wheelingbehavior in the presence of an inductive load. Zerodead-time (ZDT) technology maintains state-of-the-artefficiency and THD+N performance by allowing the outputFETs to switch simultaneously without cross conduction.A patented spread-spectrum modulationscheme eliminates the need for output filtering found intraditional Class D devices. These design conceptsreduce component count and extend battery life.The MAX9773 offers two modulation schemes: a fixedfrequency(FFM) mode, and a spread-spectrum (SSM)mode that reduces EMI-radiated emissions. TheMAX9773 oscillator can be synchronized to an externalclock through the SYNC input, allowing synchronizationof multiple Maxim Class D amplifiers. The syncoutput (SYNC_OUT) can be used for a master-slaveapplication where more channels are required. TheMAX9773 features a fully differential architecture, a fullbridge-tied load (BTL) output, and comprehensiveclick-and-pop suppression. The device features internallyset gains of 12dB, 15.6dB, 20dB, and 26dBselected through two gain-select inputs, further reducingexternal component count.The MAX9773 features high 80dB PSRR, less than0.1% THD+N, and SNR in excess of 88dB. Short-circuitand thermal-overload protection prevent the devicefrom being damaged during a fault condition. TheMAX9773 is available in 24-pin thin QFN-EP (4mm x4mm x 0.8mm), and 20-bump UCSP™ (2mm x 2.5mm x0.6mm) packages. The MAX9773 is specified over theextended -40°C to +85°C temperature range.ApplicationsCellular/Multimedia PhonesNotebooksHandheld Gaming ConsolesMP3 Players
