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.
设计了一个基于SOC系统的触摸屏逐次逼近型结构的10 bit 2Msps模数转换器(ADC)。高精度比较器和Bootstrap开关应用于设计电路中,提高了芯片速度和降低了功耗。芯片采用SMIC0.18μm 1P6M CMOS工艺流片,版图面积为0.25mm2,2MHz工作时平均功耗为3.1mW。输入频率320kHz时,信噪比(SNR)为56dB,ENOB为9.05bit,无杂散动态范围(SFDR)为66.56dB,微分非线性(DNL)为0.8LSB,积分非线性(INL)为1.4LSB。
