A 0.027-mm2 Self-Calibrating Successive Approximation ADC Core in 0.18-µm CMOS

We present a 10-bit 1-MS/s successive approximation analog-to-digital converter core including a charge redistribution digitalto-analog converter and a comparator. A new linearity calibration technique enables use of a nearly minimum capacitor limited by kT/C noise. The ADC core without digital control blocks has been fabricated in a 0.18μm CMOS process and consumes 118 μW at 1.8 V power supply. Also, the active area of ADC core is realized to be 0.027 mm2. The calibration improves the SNDR by 13.4 dB and the SFDR by 21.0 dB. The measured SNDR and SFDR at 1 kHz input are 55.2 dB and 73.2 dB respectively. key words: analog to digital converter, charge redistribution type digital to analog converter, successive approximation architecture, calibration technique