An 81.6dB SNDR 15.625MHz BW 3rd Order CT SDM with a True TI NS Quantizer

Abstract

This paper presents a continuous-time (CT) sigma-delta modulator (SDM) with a time-interleaved (TI) noise-shaping (NS) quantizer (QTZ). Complete parallelization of the NS QTZ operations relaxes loop filtering and residue integration and enables a high (6-bit) QTZ resolution. The 28nm CMOS prototype consumes 6.4mW at 500MS/s. The measured SNDR is 81.6dB for a 15.625MHz bandwidth. The corresponding Schreier FoMSNDR is 175.5dB.