A 9-GS/s 1.125-GHz BW Oversampling Continuous-Time Pipeline ADC Achieving −164-dBFS/Hz NSD

An oversampled continuous-time (CT) pipeline ADC clocked at 9 GHz achieving 1.125-GHz bandwidth and −164 dBFS/Hz average small-signal noise density is presented. In contrast to traditional discrete-time (DT) pipeline ADCs, the system processes the signals in CT form throughout all the pipeline stages and thus sampling-induced artifacts such as aliasing and high-peak ADC driving current are mitigated. Despite the oversampled nature of the ADC, its digitization bandwidth is on par with that of traditional non-interleaved DT pipeline ADCs since CT signal processing is not constrained by settling time requirements. The ADC was fabricated in a 28-nm CMOS process technology and consumes 2.3 W.