A CMOS wide-range temperature sensor with process compensation and second-order calibration for Battery Management Systems

This paper presents a temperature sensor with process compensation and second-order calibration for Battery Management Systems (BMS). Particularly, the second-order calibrated CTAT and PTAT sensors utilizing a current mirror and an n-well resistor are used to eliminate the second-order term of the temperature coefficient such that the relationship between the output voltage and the temperature is linearized. The proposed temperature sensor is implemented using a typical 0.18 μm CMOS process. The core area and power of the proposed temperature sensor are 0.177 mm² and 2.0 mW, respectively. In the range from -40°C to 125°C, the worst deviation of the temperature sensor is -1.49°C ~ +2.13°C at FF, TT, and SS corners, respectively. The maximum non-linearity reduction of second-order calibrated CTAT and PTAT sensors are 72.5% and 90.5%, respectively.