An On-Chip CMOS Temperature Sensor Using Self-Discharging P-N Diode in a [Formula Omitted]-[Formula Omitted] Loop

• Published in: IEEE transactions on circuits and systems. I, Regular papers Vol. 65; no. 6; p. 1887
• Main Authors: Chowdhury, Golam, Hassibi, Arjang
• Format: Journal Article
• Language: English
• Published: New York The Institute of Electrical and Electronics Engineers, Inc. (IEEE) 01.01.2018
• Subjects: Calibration; CMOS; Discharge; Figure of merit; Leakage current; Sensors; Temperature dependence; Temperature sensors
• ISSN: 1549-8328; 1558-0806
• DOI: 10.1109/TCSI.2017.2774040

A CMOS temperature sensor to monitor on-chip distributed thermal profile of high-performance system-on-chips (SoCs) is presented. The architecture of this sensor utilizes a self-discharging p-n diode to implement a first-order delta-sigma (Δ-Σ) loop. To determine the on-chip temperature, the temperature-dependent reverse-bias leakage current of the diode is measured. The sensor is implemented in a 0.18-μm CMOS process and it occupies a small area of 550μm2. Performance measurements demonstrate the on-chip sensor inaccuracies of ±0.1 °C (3σ) with calibration, and ±0.5 °C (3σ) without any calibration, over 35 °C-100 °C, which is the functional temperature range of current high-performance SoCs. The sensor, excluding the digital and any reference generators, consumes 4μW from a single 1.8-V supply. The worst case resolution of the sensor is 75 mK at 2-Hz bandwidth with the overall sensor figure of merit of 11 nJ°K2.