Abstract: As process progresses, capacitance mismatch of the successive approximation register analog-to-digital converter (SAR ADC)has an increasing impact on the speed and accuracy of the overall circuit.Aiming at the problem of capacitance mismatch in SAR ADC,which will lead to insufficient accuracy of SAR ADC,a SAR ADC capacitive mismatch calibration algorithm is proposed based on metastable detection,which can effectively solve the problem without increasing the complexity of analog circuit timing.The algorithm is applied to the 12 bit 150 MS/s SAR ADC.The simulation results show that the effective number of bits（Enob）can reach 11.93 bit and the spurious free dinamic range（SFDR）reaches 92.66 dB.

Key words: successive approximation register analog-to-digital converter, meta-stability, capacitive mismatch