Design of a highly compact on-chip temperature sensor with Ultra-Low power based on 40nm CMOS

A fully integrated 0.0088mm
²
temperature sensor in 40nm CMOS process is presented in this paper. The sensor generates temperature signal based on RC time constant, and following counter makes the temperature information available in a digital form. Measurement results show that the thermal sensor achieves a resolution of 0.43ºC from -40 ºC to 85 ºC, resolution FOM of 0.28nJ* K
²
, while consuming 30μA from 1V supply voltage. It only takes 50μs to complete one measurement. The highly compact area and extremely low power consumption meet the temperature monitoring requirements for real-time monitoring of hot spots with little additional overhead.