A 120dB-SNR 100dB-THD+N 21.5mW/channel multibit CT ΔΣ DAC

Automotive and consumer multi-channel 24 b audio systems have demanded low-cost digital-to-analog converters (DACs) which offer wide dynamic range, high linearity, small die size, and low power consumption such that the system can be housed in a small low-cost plastic package. Several 120 dB SNR audio ΔΣ DACs have been reported using either switched-capacitor or continuous-time techniques. This paper presents a continuous time (CT) area optimized multibit DAC which achieves 120dB SNR and 100dB THD+N at 21.5mW/chan nel. This performance is achieved by using a new 3-level rotational data shuffling scheme which achieves small area and low digital activity at low signal level, and by applying low-power low-noise analog techniques.