45nm CMOS 8Ω Class-D audio driver with 79% efficiency and 100dB SNR

Abstract

Integrating audio and power management into a system-on-chip (SoC) is of interest due to reduced board area and cost. Integrated Class-D audio drivers need to drive high voltages to deliver high power across small loads; 525mW (5.8Vpp differential) across an 8Ω load working off the battery. Absence of high-voltage transistors along with high device noise (flicker), device mismatch and leakage pose design challenges in 45nm CMOS.