Title |
Time-domain Continuous-time Delta-sigma Modulator using VCO-based Integrator and GRO-based Quantizer |
Authors |
(Eunsang Lee) ; (Jaeduk Han) |
DOI |
https://doi.org/10.5573/JSTS.2022.22.4.259 |
Keywords |
Time-domain; continuous-time delta-sigma modulator (CTDSM); VCO-based integrator; GRO-based quantizer; analog-to-digital converter (ADC) |
Abstract |
This paper presents a 3rd-order time-domain continuous-time delta-sigma modulator (CTDSM) using two voltage-controlled oscillator (VCO)-based integrators and a gated ring oscillator (GRO)-based quantizer. The GRO-based quantizer has 1st-order noise-shaping characteristics without the increase of the signal transfer function (STF) order and has magnificent linearity. Also, the output of the GRO-based quantizer has an intrinsic data weighted averaging (DWA)-based dynamic element matching (DEM) pattern that is less susceptible to the DAC mismatch. The PWM signal, which is the input of the GRO-based quantizer, is generated by the VCO-based integrator without additional blocks. In the pre-layout simulation, the CTDSM consumes 3.84 mW and achieves an SNDR of 71.2 dB at a 400-MSs sampling frequency and a 10-MHz bandwidth. |