The TPA2039D1 is a 3.2 W high efficiency filter-free class-D audio power amplifier (class-D amp) with 12 dB of fixed gain in a tiny 1.21 mm x 1.16 mm wafer chip scale package (WCSP). The device requires only one external component. Features like 93% efficiency, 1.5 mA quiescent current, 0.1 A shutdown current, 82-dB PSRR, 27 V output noise and improved RF immunity make the TPA2039D1 class-D amplifier ideal for cellular handsets. A fast start-up time of 4 ms with no audible pop makes the TPA2039D1 ideal for PDA and smart-phone applications.