A 0.8-V Resistor-Based Temperature Sensor in 65-nm CMOS With Supply Sensitivity of 0.28 °C/V

• Published in: IEEE journal of solid-state circuits Vol. 53; no. 3; pp. 906 - 912
• Main Authors: Park, Hyunmin, Kim, Jintae
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.03.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Analog-digital conversion; CMOS; Conversion; Converters; Electric potential; Interpolation; Low supply sensor; ratiometric sensing; resistor-based temperature sensor; Resistors; Sensitivity; Sensors; supply insensitive temperature sensor; System-on-chip; Temperature dependence; Temperature measurement; Temperature sensors; Voltage generators
• ISSN: 0018-9200; 1558-173X
• DOI: 10.1109/JSSC.2017.2788878

A 0.8-V resistor-based CMOS temperature sensor in 65-nm CMOS process with low supply sensitivity is presented. The temperature-to-voltage conversion gain is maximized by utilizing two types of on-chip resistors with positive and negative temperature coefficient. Reusing the resistor sensor frontend as a reference, the voltage generator of the subsequent A/D converter inherently removes the supply dependence of temperature-to-digital conversion. A 10-bit sub-ranging A/D converter employing 5-bit amplifying interpolation D/A converter enables low-voltage and low-noise A/D conversion. Over a range of -45 °C ~ 85 °C, the proposed sensor achieves 0.12 °C rms temperature resolution with a conversion time of 10 μs. After a 2-point calibration, the sensor achieves an inaccuracy of less than +1.6/-1 °C while consuming 47 μW from 0.8-V supply voltage. Measured supply sensitivity is 0.28 °C/V over 0.6 ~1.2 V, which is one of the lowest ever reported among sub-1-V temperature-to-digital converter designs.