A 0.7 V Relative Temperature Sensor With a Non-Calibrated src='/images/tex/31677.gif' alt='pm 1~^{circ}{rm C}'> 3 src='/images/tex/358.gif' alt='sigma '> Relative Inaccuracy

摘要

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 7 small remote sensor nodes is implemented on the chip with a deployment density of 49/0.81 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 to 125. The relative sensing inaccuracies without calibration are less than , and 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 experimen- ally demonstrated and a 1.8 on-chip temperature gradient was detected.