A Boosted 3.5W, -81.6dB THD+N, 92.6% Total Efficiency, Battery-Powered Class-D Audio Amplifier with True-Zero-Switching Achieving Quiescent Current of 0.9mA

This paper presents a battery-powered Class-D audio amplifier (CDA). The single-stage topology boosts the output to up to $2 \times$ of the battery voltage using a flying capacitor directly mounted on the die. The true-zero-switching (TZS) minimizes quiescent current to 0.9mA. Fabricated in a 180nm, the chip achieves a peak efficiency of 92.6% with a maximum power of 3.56W. A peak THD+N of −81.6dB at 1kHz was measured.