Low distortion CMOS class-D amplifier with double-band hysteresis

Abstract

A new low distortion class-D switching power amplifier (PA) is presented using a double-band hysteresis control (DBHC) technique. This PA utilizes two Schmitt trigger comparators to realize 4-level comparison. The THD is lowered due to reduction of overshoot and Hysteresis-band. Simulation results, using a 0.13µm CMOS technology, show that in this PA the THD is improved, while it supports relatively high output power. The performance of DBHC-PA is also experimentally tested and its operation is verified by a PCB prototype amplifier. Measurements illustrate 58% THD improvement compared to conventional class-D PA.