一种CMOS温度传感器输出误差的数字校正方法

A Digital Calibration Method for Output Error of CMOS Temperature Sensors

针对CMOS温度传感器模拟校正方法需额外增加校正器件,而数字校正方法存在精度偏低的问题,提出了一种新的适用于CMOS温度传感器的数字校正方法。对CMOS温度传感器的传输函数进行推导,得到温度传感结果与数字电路的关系。根据传输函数,对温度传感器数字电路中的计数器及状态机的参数进行修调,通过改变计数周期个数及计数初值达到校正电路的增益误差及失调误差的目的,得到温度传感器的测温结果。仿真及实测结果表明,采用所提出的校正方法设计的温度传感器,在-55~125℃,测温误差小于1.04℃,满足高精度应用需求。

For CMOS temperature sensor,analog calibration method requires additional correction devices,and the digital calibration method has the problem of low accuracy.A new digital correction method for CMOS temperature sensor was proposed.By deriving the transfer function of the CMOS temperature sensor,the relationship between temperature sensing result and the digital circuit was obtained.Then,according to the transfer function,the parameters of counter and state machine in digital circuit of the temperature sensor were adjusted.By changing the number of counting cycles and the initial value of counting to correct the gain error and offset error,and the temperature measurement results of the temperature sensor were obtained.Simulation and measurement results show that the temperature sensor using the proposed calibration method has a temperature measurement error less than 1.04℃at-55-125℃,which can meet the requirements of high accuracy applications.