The NCP2991 is an audio power amplifier designed for portable communication device applications such as mobile phone applications. The NCP2991 is capable of delivering 1.35 W of continuous average power to an 8.0 W BTL load from a 5.0 V power supply, and 1.1 W to a 4.0 W BTL load from a 3.6 V power supply. The NCP2991 provides high quality audio while requiring few external components and minimal power consumption. It features a low-power consumption shutdown mode, which is achieved by driving the SHUTDOWN pin with logic low. The NCP2991 contains circuitry to prevent from "pop and click" noise that would otherwise occur during turn-on and turn-off transitions. It is a zero pop noise device when a single ended or a differential audio input is used. For maximum flexibility, the NCP2991 provides an externally controlled gain (with resistors). In addition, it integrates 2 different Turn On times (15 ms or 30 ms) adjustable with the TON pin. Due to its superior PSRR, it can be directly connected to the battery, saving the use of an LDO. This device is available in a 9-Pin Flip-Chip CSP (Lead-Free).