Hybrid charge-sharing charge-redistribution DAC for successive approximation analog-to-digital converters

摘要

A hybrid D/A converter is provided including first and second D/A converters. The first D/A converter receives a digital signal having an input voltage and converts a first most-significant-bit of the digital signal to be converted to an analog signal. The first D/A converter includes first capacitors, which are charged by the input voltage and reference voltages during a sampling phase of the digital signal. Charges of the first capacitors are shared during successive approximations of first bits of the digital input signal received by the hybrid D/A converter. The second D/A converter converts a first least-significant-bit of the digital input signal. The second D/A converter includes second capacitors, which are charged based on a common mode voltage during the sampling phase. The second D/A converter performs charge redistribution by connecting the second capacitors to receive the reference voltages during successive approximations of second bits of the digital signal.