A Robust Continuous Time Loop Filter PWM Class D Amplifier with High Linearity and Good Immunity to Process Variations

摘要

This paper describes a robust PWM class D amplifier with high linearity and good immunity to process variations. By using the proposed adaptive triangular wave generator (ATG), 0.0042% THD+N and 99.2dB dynamic range is achieved in this design. The standard deviation of THD+N ratio over 22 samples can be smaller by 4 times compared to the results without the adaptive triangular wave generator. This chip integrates power MOS stages and 2 channel design. The supply voltage is from 3V to 5.5V and the die area is 2.45mm × 2.9mm.