摘要 : This paper presents a code-pattern-driven digital calibration technique for medium- to high-resolution charge-redistribution SAR ADCs, which is in background and on chip. An efficient mismatch detection circuit based on output cod... 展开 This paper presents a code-pattern-driven digital calibration technique for medium- to high-resolution charge-redistribution SAR ADCs, which is in background and on chip. An efficient mismatch detection circuit based on output code pattern is utilized to evaluate the radix error in CDAC by adding one bit trial in conversion process. Under certain condition, mismatch extraction and calibration for certain bit is triggered, detecting the magnitude of mismatch errors and correcting the bit weight simultaneously in a iterative loop during ADC operation. The proposed calibration needs extra few digital circuits and no computation, which is validated with a 14-bit SAR ADC. The simulation results show that, with calibration, the signal to noise and distortion ratio and spurious-free dynamic range are improved to 81.83-91.96 dB after calibration from 51.73 and 49.26 dB, respectively. 收起