1.2W, Low-EMI, Filterless, Class D Audio Amplifier

Active: In Production.

The MAX9746 mono Class D audio power amplifier provides Class AB amplifier performance with Class D efficiency, conserving board space and extending battery life. The MAX9746 is designed specifically for systems using 1.8V logic interface. Using a Class D architecture, the MAX9746 delivers 1.2W into an 8Ω load while offering efficiencies near 90%. A low-EMI modulation scheme renders the traditional Class D output filter unnecessary.

The MAX9746 offers two modulation schemes: a fixed-frequency (FFM) mode, and a spread-spectrum (SSM) mode that reduces EMI-radiated emissions due to the modulation frequency. Furthermore, the MAX9746 oscillator can be synchronized to an external clock through the SYNC input, allowing the switching frequency to be user defined. The SYNC input also allows multiple MAX9746s to be cascaded and frequency locked, minimizing interference due to clock intermodulation. The device utilizes a fully differential architecture, a fullbridged output, and comprehensive click-and-pop suppression. The gain of the MAX9746 is set internally further reducing external component count.

The MAX9746 features high 72dB PSRR, a low 0.1% THD+N, and SNR in excess of 90dB. Short-circuit and thermal-overload protection prevent the device from damage during a fault condition. The MAX9746 is available in a 12-bump UCSP™ (1.5mm x 2mm x 0.6mm) package. The MAX9746 is specified over the extended -40°C to +85°C temperature range.

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