Continuous-Time Pipelined ADC: A Breed of Continuous-Time ADCs for Wideband Data Conversion

The continuous-time (CT) pipelined analog-to-digital converter (ADC) is an emerging ADC architecture suitable for wide- bandwidth (BW) digitization in fully integrated receiver applications. It inherits the integration-friendly features of CT $\Delta \Sigma $ ADCs, such as inherent anti-aliasing, while achieving the wide- BW operation originating from discrete-time (DT) pipelined ADCs. In this review article, we introduce a gain-centric ADC model and apply the key criteria derived from the model to transform a DT pipelined ADC into a CT pipelined ADC. We then discuss the design considerations and essential building blocks of the CT pipelined ADC. Finally, we examine several implementations of this architecture with their highlights and challenges.