A capacitor self-calibration circuit used in a successive approximation analog-to-digital converter (SA-ADC) is presented. This capacitor self-calibration circuit can calibrate erroneous data and work with the ADC by adding an additional clock period. This circuit is used in a 10 bit 32 Msample/s time-interleaved SA- ADC. The chip is implemented with Chart 0. 25 μm 2. 5 V process and totally occupies an area of 1.4 mm× 1.3 mm. After calibration, the simulated signal-to-noise ratio (SNR) is 59. 586 1 dB and the spurious-free dynamic range (SFDR) is 70. 246 dB at 32 MHz. The measured signal-to-noise and distortion ratio (SINAD) is 44. 82 dB and the SFDR is 63. 760 4 dB when the ADC samples a 5.8 MHz sinusoid wave.