A 0.7 V Relative Temperature Sensor With a Non-Calibrated +/- 1 degrees C 3 sigma Relative Inaccuracy

作者：Lu Li^*; Vosooghi Bozorgmehr; Dai Liang; Li Changzhi

来源：IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS, 2015, 62(10): 2434-2444.

DOI：10.1109/TCSI.2015.2471555

• Dynamic threshold MOSFET
• low-voltage
• multi-location thermal monitoring
• relative accuracy
• Schottky barrier diode
• subthreshold MOSFET
• temperature sensor

This paper presents a new low-voltage relative temperature sensor for multi-core digital processor on-chip thermal management in a 180 nm CMOS process. Three types of sensing diodes including Schottky barrier diode (SBD), subthreshold MOSFET diode and dynamic threshold MOSFET (DTMOS) diode have been investigated for low-voltage operation, while traditional parasitic PNP-bipolar junction transistor (BJT) diodes are implemented to provide a performance reference. A matrix of 7 x 7 small remote sensor nodes is implemented on the chip with a deployment density of 49/0.81 mm(2) and sharing the same bias current generator, control logic, and data converter. The measured minimum supply voltage (not including the clock control block) of the sensor is 0.7 V over -55 degrees C to 125 degrees C. The relative sensing inaccuracies (3 sigma) without calibration are less than +/- 1.5 degrees C, +/- 1.2 degrees C and +/- 1 degrees C for the designs based on SBD, subthreshold MOSFET, and DTMOS, respectively. To the best of the authors' knowledge, this is the first time that non-calibrated relative sensing accuracy is reported for SBD-based and DTMOS-based temperature sensors, and the best reported result for the design based on subthreshold MOSFET. The absolute inaccuracies with calibration-per-chip are also presented. Furthermore, the multi-location thermal monitoring function has been experimentally demonstrated and a 1.8 degrees C/mm on-chip temperature gradient was detected.

• 出版日期2015-10