The TPA3124D2 is a 15-W (per channel), efficient, class-D audio power amplifier for driving stereo speakers in a single-ended configuration; or, a mono speaker in a bridge-tied-load configuration. The TPA3124D2 can drive stereo speakers as low as 4 . The efficiency of the TPA3124D2 eliminates the need for an external heat sink when playing music. The gain of the amplifier is controlled by two gain select pins. The gain selections are 20, 26, 32, and 36 dB.