A self-calibration method for capacitance mismatch in SAR ADC with split-capacitor DAC

作者：Dai Peng; Zhao Yiqiang^*; Sheng Yun; Zhang Yun

来源：Microelectronics Journal, 2015, 46(6): 431-438.

DOI：10.1016/j.mejo.2015.03.011

• Split-DAC
• Self-calibration
• Capacitance mismatch
• Calibration DAC array

A self-calibration method to calibrate the nonlinearity due to capacitance mismatch in successive approximation register (SAR) analog-to-digital converter (ADC) is presented. It focuses on calibrating the most significant bit (MSB) array in the split-capacitor main DAC (split-MDAC) by using a calibration DAC (CDAC) that contains multiple sub-CDACs. Every bit in MSB array has its corresponding sub-CDAC in CDAC, which enhances the calibration efficiency. To verify the calibration method, a 14 bit, 50016/s SAR ADC is implemented, and it is manufactured in 0.35 mu m 2P4M CMOS process. The measured results show that the proposed calibration method can assist this SAR ADC to achieve better static and dynamic performance, and its ENOB is improved from 9 bit to 11.98 bit at Nyquist input frequency.

• 出版日期2015-6
• 单位天津大学