20-W stereo, 10- to 26-V supply, digital input, closed loop Class-D audio amplifier w/ EQ & DRC

The TAS5708 is a 20-W, efficient, digital audio power amplifier for driving stereo bridge-tied speakers. A 32-bit datapath eliminates the need for pre-scaling before processing and preserves signal integrity without sacrificing dynamic range. A digital audio processor with fully programmable digital filters allows designers to custom tune speakers for optimum sound in small enclosures. A programmable DRC can adjust power levels for a scaleable design while also enabling night-mode listening modes.

The closed-loop architecture allows the device to operate from poorly regulated supplies. Figure 1 below shows the benefit of the feedback architecture when a noisy supply (1kHz, 500mVpp ripple) modulates a 10kHz audio input. The figure shows a 40dB improvement in sideband suppression when compared to an open-loop design. This correlates directly to a 24dB improvement in distortion as seen in Figure 2.