A 72dB-SNDR rail-to-rail successive approximation ADC
When the voltage of analog input signal equals to supply voltage, the general successive approximation ADC is difficult to convert it into digital signal correctly. So this paper introduces a new successive approximation ADC which can convert rail-to-rail input range and reduce sampling time through a track-and-hold circuit. Measurement results show that the peak SNDR of this ADC reaches 72dB and signal effective bandwidth up to 1.25MHz. It consumes 1mW in the test, corresponding to a figure of merit of 123fJ/conversion-step.