The TPA2036D1 is a 2.5-W high efficiency filter-free class-D audio power amplifier (class-D amp) in a 1,45 mm × 1,45 mm wafer chip scale package (WCSP) that requires only three external components. Features such as 88% efficiency, –75-dB PSRR, improved RF immunity, and 8 mm2 total PCB area make TPA2036D1 ideal for cellular handsets. A fast start-up time of 1 ms with minimal pop makes TPA2036D1 ideal for portable applications. In cellular handsets, TPA2036D1 is capable of driving the earpiece, speaker phone, and melody ringer. TPA2036D1 allows independent gain while summing signals from separate sources, and has a low 36 µVRMS noise floor, A-weighted.