25W/50W, Filterless, Spread-Spectrum, Stereo/Mono, Class D Amplifier

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.

Applications

* LCD TVs * PC/HiFi Audio Solutions * PDP TVs

* 2 x 25W Output Power in Stereo Mode (8Ω, THD = 10%)

* 1 x 50W Output Power in Mono Mode (4Ω, THD = 10%)

* High Efficiency: Up to 87%

* Filterless Class D Amplifier

* Unique Spread-Spectrum Mode

* Programmable Gain (+22dB, +25dB, +29.5dB, +36dB)

* High PSRR (90dB at 1kHz)

* Differential Inputs Suppress Common-Mode Noise

* Shutdown and Mute Control

* Integrated Click-and-Pop Suppression

* Low 0.1% THD+N

* Current Limit and Thermal Protection

* Programmable Thermal Flag

* Clock Synchronization Input and Output

* Available in Thermally Efficient, Space-Saving Package: 56-Pin TQFN