A 320MHz BW NS TD-ADC Assisted C/DT Hybrid Pipelined ADC with SAB-based Residue Amplifying Filter

With the advent of WLAN technologies, over 320 MHz BW and $\gt 65 \mathrm{~dB}$ DR ADCs become indispensable to support newly developed WiFi standards. Three classic solutions can reach the said targets but involve various compromises (Fig. 1 top). CT MASH ADCs [1] rely on a relatively high OSR $(\geqslant 7)$ as well as NS order to accommodate the adequate noise spectral density (NSD), limiting the energy efficiency. The CT pipeline (PIPE) ADC [2–3] obviates the feedback loop and its 1st stage energy effectively provides preliminary quantization, residue generation, amplification, and filtering. However, the backend CT quantization can be power-hungry [2] [4]. The DT NS pipeline ADC offers a low-power alternative [5] but loses the intrinsic anti-aliasing (AA) ability from its CT counterparts. This work hybridizes CT and DT NS PIPE, gaining the pros from the CT PIPE front-end and DT PIPE backend. Together with the Single amplifier biquad (SAB) - Residue Amplifying Filter (RAF) and NS TD-QTZ, the C/DT PIPE ADC demonstrates superior energy efficiency over CT MASH ADCs with 320MHz BW.