A 1-V 10-bit 80-MS/s 1.6-mW SAR ADC in 65-nm GP CMOS

This paper presents a 10-bit 80-MS/s successive approximation register（SAR） analog-to-digital converter （ADC） suitable for integration in a system on a chip（SoC）.By using the top-plate-sample switching scheme and a split capacitive array structure,the total capacitance is dramatically reduced which leads to low power and high speed.Since the split structure makes the capacitive array highly sensitive to parasitic capacitance,a three-row layout method is applied to the layout design.To overcome the charge leakage in the nanometer process,a special input stage is proposed in the comparator.As 80 MS/s sampling rate for a 10-bit SAR ADC results in around 1 GHz logic control clock,and a tunable clock generator is implemented.The prototype was fabricated in 65 nm 1P9M （one-poly-nine-metal） GP（general purpose） CMOS technology.Measurement results show a peak signal-to-noise and distortion ratio（SINAD） of 48.3 dB and 1.6 mW total power consumption with a figure of merit（FOM） of 94.8 fJ/conversion-step.