A 1.3-mW per-channel 103-dB SNR stereo audio DAC with class-D head-phones amplifier in 65nm CMOS

The stereo audio DAC with novel single-ended class-D amplifier achieving a 103-dB SNR is fully integrated in a 65 nm CMOS technology. Novel asymmetric pulse-width modulation (PWM) is applied to minimize switching noise and nonlinearity in the class-D amplifier. The adjustable delta-sigma modulator is also used to suppress supply-voltage modulation. All the functions needed for portable audio playback are implemented in a 0.53-mm
²
area dissipating only 1.3-mW per channel from a 2.5-V supply.