In this paper, we focus on practical issues in implementing a calibration technique for medium-resolution, highspeed flash analogtodigital converters (ADCs). In [1], we theoretically describ the calibration techniqu...In this paper, we focus on practical issues in implementing a calibration technique for medium-resolution, highspeed flash analogtodigital converters (ADCs). In [1], we theoretically describ the calibration technique and perform a behaviorallevel simulation to test its functionality [1]. In this work, we discuss some issues in transistorlevel implementation. The predominant factors that contribute to static errors such as reference generator mismatch and trackandhold (T/H) gain error can be treated as inputreferred offsets of each comparator. Using the proposed calibration technique, these errors can be calibrated with minimal detriment to the dynamic performance of the converter. We simulate a transistorlevel implementation of a 5-bit, 1 GHz ADC in a 1.2 V, 65 nm CMOS process. The results show that DNL can be improved from 2.5 LSB to below 0.7 LSB after calibration, and INL can be improved from 1.6 LSB to below 0.6 LSB after calibration.展开更多
文摘In this paper, we focus on practical issues in implementing a calibration technique for medium-resolution, highspeed flash analogtodigital converters (ADCs). In [1], we theoretically describ the calibration technique and perform a behaviorallevel simulation to test its functionality [1]. In this work, we discuss some issues in transistorlevel implementation. The predominant factors that contribute to static errors such as reference generator mismatch and trackandhold (T/H) gain error can be treated as inputreferred offsets of each comparator. Using the proposed calibration technique, these errors can be calibrated with minimal detriment to the dynamic performance of the converter. We simulate a transistorlevel implementation of a 5-bit, 1 GHz ADC in a 1.2 V, 65 nm CMOS process. The results show that DNL can be improved from 2.5 LSB to below 0.7 LSB after calibration, and INL can be improved from 1.6 LSB to below 0.6 LSB after calibration.