Bong-joo Kim

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-mm2 area dissipating only 1.3-mW per channel from a 2.5-V supply.

A self-calibration 103-dB SNR stereo audio DAC with true-GND class-D headphone drivers in 45nm CMOS

A stereo audio DAC with ground-centered class-D headphone drivers is fully integrated in a 45nm CMOS technology. A built-in self-calibration is proposed to minimize DC offset voltage causing static power dissipation. The asymmetric averaging PWM is also applied to improve linearity and suppress switching noise and loss. The measured SNR and DR are 103dB and 98dB, respectively.