A Resistor-Based Sub-1-V CMOS Smart Temperature Sensor for VLSI Thermal Management

Abstract

This paper presents a novel low-voltage CMOS smart temperature sensor targeted for VLSI thermal management. A polyresistor is used as the sensing element and digitization is performed in the time domain. The proposed temperature-sensing concept can be realized with simple circuits that operate at low supply voltages, which are compatible with the digital circuits in VLSI systems. Fabricated in 90-nm CMOS, the sensor can operate with a supply voltage as low as 0.8 V and features a supply sensitivity of 4 °C/V. After 50-sample moving-average and a two-point calibration at 25 °C and 45 °C, the design achieves an inaccuracy of −0.6 °C/0.8 °C over −40 °C–125 °C. It dissipates only 11.8 $\mu $ W at a sampling rate of 5 kS/s from a 0.9-V nominal supply.