An ultra-small on-chip sensor for temperature and thermal gradient measurements

An ultra-small, low-power CMOS temperature sensor designed for multi-site temperature and temperature gradient monitoring to support power/thermal management in integrated circuits where electromigration limits system reliability is proposed. The temperature sensor utilizes the temperature characteristics of the threshold voltage of MOS transistors to sense temperature and is highly linear throughout the temperature range required for power/thermal management and has good accuracy throughout this range with calibration at a single temperature. Prototype temperature sensors have been designed in a TSMC 0.18μm process with a 1.8V supply voltage. The sensing device has a very small die area of only 2.5μm×6.2μm and a low power consumption of about 0.95μW at a 1% duty cycle making it suitable for multi-site thermal monitoring.