Time-Encoding Analog-to-Digital Converters: Bridging the Analog Gap to Advanced Digital CMOS-Part 1: Basic Principles

• Published in: IEEE solid state circuits magazine Vol. 12; no. 2; pp. 47 - 55
• Main Authors: Gielen, Georges G.E., Hernandez, Luis, Rombouts, Pieter
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.01.2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Analog circuits; Analog to digital conversion; Analog to digital converters; Basic converters; Circuit design; Circuits; Cloud computing; CMOS; CMOS technology; Digital electronics; Digital signal processing; Global Positioning System; GSM; Machine learning algorithms; Power consumption; Principles; Temperature measurement; Temperature sensors; Voltage controlled oscillators
• ISSN: 1943-0582; 1943-0590
• DOI: 10.1109/MSSC.2020.2987536

The scaling of CMOS technology deep into the nanometer range has created challenges for the design of highperformance analog ICs. The shrinking supply voltage and presence of mismatch and noise restrain the dynamic range, causing analog circuits to be large in area and have a high power consumption in spite of the process scaling. Analog circuits based on time encoding [1], [2] and hybrid analog/digital signal processing [3] have been developed to overcome these issues. Realizing analog circuit functionality with highly digital circuits results in more scalable design solutions that can achieve excellent performance. This article reviews the basic principles of time encoding applied, in particular, to analog-to-digital converters (ADCs) based on voltage-controlled oscillators (VCOs), one of the most successful time-encoding techniques to date.