A 5.76GS/s 180MHz-BW 74.1dB-DR 2x TI Extrapolated CT DSM with Broadband Hybrid-Inputs Current-Mode Adder in 28nm CMOS

In recent years, Gigahertz-rate oversampled CT DSMs have been consistently explored to pursue a larger bandwidth (BW) [1] –[4]. Note that the usable oversampling ratio (OSR) is seriously limited (i.e. below 10) in those works owing to the restrained clock rate. A low OSR results in poor quantization efficiency, thus limiting the achievable dynamic range (DR). In such an ultra-low-OSR context, multi-stage noise-shaping (MASH) topology [2–3] can achieve $\sim 70 \mathrm{~dB}$ DR at 360 MHz and 465 MHz BWs, respectively. However, those broadband MASH CT DSMs significantly suffer from quantization noise (QN) leakage, requiring digital calibrations, which consume large power and area.