Time-domain Continuous-time Delta-sigma Modulator using VCO-based Integrator and GRO-based Quantizer

• Published in: Journal of semiconductor technology and science Vol. 22; no. 4; pp. 259 - 265
• Main Authors: Lee, Eunsang, Han, Jaeduk
• Format: Journal Article
• Language: English
• Published: 대한전자공학회 01.08.2022
• Subjects: 전기공학; Time-domain; VCO-based integrator; continuous-time delta-sigma modulator (CTDSM); analog-to-digital converter (ADC); GRO-based quantizer
• ISSN: 1598-1657; 2233-4866
• DOI: 10.5573/JSTS.2022.22.4.259

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. KCI Citation Count: 0