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.