Texas Instruments' TAS2552 is a high-efficiency Class-D audio power amplifier with advanced battery current management and an integrated Class-G boost converter. The device constantly measures the current and voltage across the load and provides a digital stream of this information.
The Class-G boost converter generates the Class-D amplifier supply rail. During low Class-D output power, the boost improves efficiency by deactivating and connecting VBAT directly to the Class-D amplifier supply. When high-power audio is required, the boost quickly activates to provide significantly louder audio than a stand-alone amplifier connected directly to the battery.
The AGC automatically adjusts Class-D gain to reduce battery current at end-of-charge voltages, preventing output clipping, distortion, and early system shutdown. The fixed gain is adjustable via I²C. The gain range is –7 dB to +24 dB in 1 dB steps.
In addition to a differential mono analog input, the TAS2552 has built-in a 16-bit D/A converter used with a digital input. Moving the D/A converter from the digital host processor into the integrated amplifier process provides better dynamic performance at lower system cost. Additionally, since the PCB routing is digital rather than analog, sensitivity to external perturbations such as GSM frame-rate noise is decreased at the system level.