An area-efficient 55 nm 10-bit 1-MS/s SAR ADC for battery voltage measurement

Abstract

An area-efficient CMOS 1-MS/s 10-bit charge-redistribution SAR ADC for battery voltage measurement in a SoC chip is proposed. A new DAC architecture presents the benefits of a low power approach without applying the common mode voltage. The threshold inverter quantizer (TIQ)-based CMOS Inverter is used as a comparator in the ADC to avoid static power consumption which is attractive in battery-supply application. Sixteen level-up shifters aim at converting the ultra low core voltage control signals to the higher voltage level analog circuit in a 55 nm CMOS process. The whole ADC power consumption is 2.5 mW with a maximum input capacitance of 12 pF in the sampling mode. The active area of the proposed ADC is 0.0462 mm2 and it achieves the SFDR and ENOB of 65.6917 dB and 9.8726 bits respectively with an input frequency of 200 kHz at 1 MS/s sampling rate.