Class-D amplifier enables efficient operation at full-power, idle and standby

The TPA3220, from Texas Instruments, is a pad-down Class-D amplifier that allows efficient operation at full-power, idle and standby. The device offers closed-loop feedback with a bandwidth up to 100kHz, which gives low distortion across the audio band and produces excellent sound quality. The device runs with either AD or low idle-current HEAD modulation and can drive up to 2 x 60W continuously or 2 x 110W peak into 4Ohm load with the thermal pad on bottom connected to the PCB. The amplifier offers a single-ended or differential analog-input interface that supports up to 2VRMS with four selectable gains: 18dB, 24dB, 30dB and 34dB, 20dB, 26dB, 32dB and 36dB. The device also achieves >90% efficiency, low idle power (<0.25W) and ultra-low standby power (<0.1W). This is made achievable through the use of 70mOhm MOSFETs, an optimised gate drive scheme and low-power operating modes. amplifier includes a built-in LDO for simple integration in single-power-supply systems. To simplify the design further, the device combines essential protection features including undervoltage, short circuit, cycle-by-cycle current limit, clipping detection, overtemperature warning and shutdown, as well as DC speaker protection.