An Energy Efficient Time-Domain Temperature Sensor for Low-Power On-Chip Thermal Management

Because temperature variations significantly affect the performance and reliability of highly integrated chips, the thermal management of such chips is an important issue. In this paper, a time-domain process variation calibrated temperature sensor is proposed for on-chip thermal management. For a suitable on-chip implementation, the digitally converted temperature-dependent time signal is used to reduce the area and power consumption of the chip. The proposed temperature sensor is fabricated using a 0.13- μm CMOS technology and has an active area of 0.031 mm². Measurement results show an energy consumption of 0.67 nJ/conversion at a 430 kHz conversion rate, with 1.2 V supply voltage. Using one-point calibration, the sensing error is found to range from -0.63°C to 1.04°C over a temperature range of 20°C to 120°C.