MAX9770

The MAX9770 combines a mono, filterless, Class Dspeaker amplifier and stereo DirectDrive headphone amplifiers in a single device. The MAX9770 operates from a single 2.5V to 5.5V supply and includes features that reduce external component count, system cost, board space, and offer improved audio reproduction. The speaker amplifier makes use of Maxim's patented Class D architecture, providing Class AB performance with Class D efficiency, conserving board space, and extending battery life. The speaker amplifier delivers 1.2W into an 8Ω load while offering efficiencies above 85%. A spread-spectrum scheme reduces radiated emissions caused by the modulation frequency. Furthermore, the MAX9770 oscillator can be synchro- nized to an external clock through the SYNC input, avoiding possible problem frequencies inside a system. The speaker amplifier features a low 0.025% THD+N, high 70dB PSRR, and SNR in excess of 90dB.

 The speaker amplifier makes use of Maxim's patentedClass D architecture, providing Class AB performancewith Class D efficiency, conserving board space, andextending battery life. The speaker amplifier delivers1.2W into an 8Ωload while offering efficiencies above85%. A spread-spectrum scheme reduces radiatedemissions caused by the modulation frequency.Furthermore, the MAX9770 oscillator can be synchro-nized to an external clock through the SYNC input,avoiding possible problem frequencies inside a system.The speaker amplifier features a low 0.025% THD+N,high 70dB PSRR, and SNR in excess of 90dB.

The headphone amplifiers feature Maxim's patentedDirectDrive architecture that produces a ground-refer-enced output from a single supply, eliminating the needfor large DC-blocking capacitors. The headphone ampli-fiers deliver up to 80mW into a 16Ωload, feature low0.015% THD+N, high 80dB PSRR, and ±8kV ESD-pro-tected outputs. A headphone sense input detects thepresence of a headphone, and automatically configuresthe amplifiers for either speaker or headphone mode.

The MAX9770 includes internally set, logic-selectablegain, and a comprehensive input multiplexer/mixer, allow-ing multiple audio sources to be selected and for truemono reproduction of a stereo source in speaker mode.Industry-leading click-and-pop suppression eliminatesaudible transients during power and shutdown cycles. Alow-power shutdown mode decreases supply currentconsumption to 0.1µA, further extending battery life.

The MAX9770 is offered in space-saving, thermally effi-cient 28-pin TQFN (5mm x 5mm x 0.8mm) and 28-pinTSSOP packages. The MAX9770 features thermal-over-load and output short-circuit protection, and is specifiedover the extended -40°C to +85°C temperature range.