A Poly Resistor Based Time Domain CMOS Temperature Sensor with 9b SAR and Fine Delay Line

• Published in: Sensors (Basel, Switzerland) Vol. 20; no. 7; p. 2053
• Main Authors: Xu, Zhiwei, Byun, Sangjin
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 06.04.2020; MDPI
• Subjects: CMOS; CMOS integrated circuits; coarse delay line; Delay lines; Energy conversion efficiency; fine delay line; Linearity; Principles; SAR; Sensors; temperature sensor; Temperature sensors; time domain; Transistors; coarse delay line; time domain; CMOS integrated circuits; SAR; temperature sensor; fine delay line
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s20072053

This paper presents a new type of time domain CMOS temperature sensor with a 9b successive approximation register (SAR) control logic and a fine delay line. We adopted an N-type poly resistor as the sensing element for temperature linearity. The chip was implemented in a standard 0.18 m 1P6M bulk CMOS process with general V transistors and the active die area was 0.432 mm . The temperature resolution was 0.49 °C and the temperature error was from -1.6 to +0.6 °C over the range of 0 to 100 °C after two-point calibration. The supply voltage sensitivity was 0.085 °C/mV. The conversion rate was 25kHz and the energy efficiency was 7.2 nJ/sample.