A Curvature Compensated BJT-based Time-Domain Temperature Sensor With An Inaccuracy of ±0.7°C From -40°C to 125°C

This paper presents a BJT-based time-domain temperature sensor with V
_BE
-curvature compensation. The temperature dependent signals from the BJT frontend are processed by the delay pulse generator to produce a temperature dependent pulse width modulation (PWM) signal for low power consumption. To further improve the sensing accuracy, the PWM signal is quantized using an on-chip current-controlled oscillator (CCO) to compensate for the intrinsic V
_BE
non-linearity. Implemented in a standard 0.18-μm CMOS process, the proposed sensor achieves an inaccuracy of ±0.7°C using only one-point calibration at 30°C, while consuming a nominal power of 5.7μW over a wide range from - 40°C to 125°C.