The AP4890B is an audio power amplifier designed for portable communication evice applications such as mobile phone applications. The AP4890B is capable of delivering 1W of continuous average power to an 8Ω BTL and with less than 1% distortion (THD+N) from a 5.0V power supply, and 350mW to a 8Ω BTL load from a 3V power supply. The AP4890B provides high quality audio while requiring few extemal components and minimal power consumption. It features a low-power shutdown mode, which is achieved by driving the SHUTDOWN pin with logic low. The AP4890B contains circuitry to prevent from “pop and click” noise that would otherwise occur during turn-on and turn-off transitions.For maximum flexibility, the AP4890B provides an externally controlled gain (with resistors), as well as an externally controlled turn-on and turn-off times (with the bypass capacitor).