Bandpass ΔΣ ADC using pipelined SAR ADC

Abstract

This Letter proposes a second-order bandpass ΔΣ ADC using a pipelined successive-approximation-register (SAR) ADC as an internal quantiser. The second-order bandpass noise-shaping is achieved by utilising the residue signal after SAR conversion and inherent delay existing in a pipelined structure. The proposed ADC can show very high resolution even with low-order noise-shaping and low oversampling ratio. Also, it shows good energy efficiency and a high sampling rate due to the use of a pipelined SAR ADC as a quantiser.