An 8Ω, 1.4W, 0.0024% THD+N Class-D Audio Amplifier with Bridge-Tied Load Half-Side Switching Mode Achieving Low Standby Quiescent Current of 660μA

Abstract

In this paper, a Class-D audio amplifier (CDA) with bridge-tied load half-side switching (BTLHS) mode is presented. The BTLHS mode through a digital pulse width subtracter (DPWS) enables a low quiescent current (IQ) by suspending the output switching in idle condition while maintaining high linearity with seamless zero-crossings and mode change. The CDA achieves 0.0024% THD+N, IQ of 0.66mA, and 95% peak efficiency on an 8Ω-speaker. The chip was fabricated in a 0.18-μm CMOS process, and it occupies 0.83mm2.