Low-Power Switching Scheme with Quarter Reference Voltage Sources for SAR ADCs

In this paper, an energy-efficient switching scheme with additional quarter-reference voltage sources in a successive approximation register (SAR) analog-to-digital converter (ADC) is proposed for low power and small area device frequency modulated continuous wave (FMCW) radar transceivers. Recently, state-of-the-art ADCs have adopted configuration that also uses Vref/2 as the reference of to improve energy capacitive digital-to-analog (CDAC). The additionally Vref/4 3Vref/4 voltages CDAC. Compared configurations use Vref/2, average energy, total capacitance CDAC are reduced by about 87.5% 50%, respectively. scheme, output gradually converges like conventional SAR ADCs, which minimizes dynamic offset deteriorates linearity ADC.