A 0.8 V, 2.6 mW, 88 dB Dual-Channel Audio Delta-Sigma D/A Converter With Headphone Driver

A 0.8 V third-order multibit DeltaSigma DAC with headphone driver is described. It is the first sub-1 V audio DeltaSigma DAC with integrated on-chip headphone driver. The dual-channel operation in digital section was efficiently realized with a time-interleaved single-channel hardware and extra registers. Using novel DAC architecture suitable for low-voltage operation, the analog section requires only one opamp per channel for the D/A conversion, low-pass filtering, and driving the headphone. Two prototype ICs (separate digital and analog chips), implemented in a 0.35 mum CMOS process, achieved an 88 dB dynamic range, while consuming 2.6 mW from a 0.8 V supply.