The MAX9709 stereo/mono, Class D audio power amplifier delivers up to 2 x 25W into an 8Ω stereo mode and 1 x 50W into a 4Ω load in mono mode while offering up to 87% efficiency. The MAX9709 provides Class AB amplifier performance with the benefits of Class D efficiency, eliminating the need for a bulky heatsink and conserving power. The MAX9709 operates from a single +10V to +22V supply, driving the load in a BTL configuration. The MAX9709 offers two modulation schemes: a fixed-frequency modulation (FFM) mode, and a spread-spectrum modulation (SSM) mode that reduces EMI-radiated emissions. The MAX9709 can be synchronized to an external clock from 600kHz to 1.2MHz. A synchronized output allows multiple units to be cascaded in the system. Features include fully differential inputs, comprehensive click-and-pop suppression, and four selectable-gain settings (22dB, 25dB, 29.5dB, and 36dB). A pin-programmable thermal flag provides seven different thermal warning thresholds. Short-circuit and thermal-overload protection prevent the device from being damaged during a fault condition. The MAX9709 is available in a 56-pin TQFN (8mm x 8mm x 0.8mm) package, and is specified over the extended -40°C to +85°C temperature range.