Power-Noise Trade-Offs in Continuous-Time Pipelined ADCs and Active Filters

The continuous-time pipelined (CTP) analog-to-digital converter is an emerging architecture that realizes the equivalent of an anti-alias filter followed by an ADC. This work compares power-noise trade-offs in CTPs with those in a filter+ADC cascade. We consider two commonly-used filter topologies, namely the Tow-Thomas and Rauch biquad structures. We show that the SNDR of an appropriately designed CTP is much higher than that achieved by a signal chain consisting of an active filter driving a Nyquist ADC. Our theory is verified using macro-model and transistor-level simulations.