一种温度电容混合传感器的接口电路

A Combined Temperature and Capacitance Sensor Interface

基于NXP 0.16μm CMOS工艺,设计并实现了一种温度、电容混合传感器的接口电路。温度传感器的前端基于双极型晶体管的温度依赖特性,将温度信息转换为与温度有关的电压信息;电容传感器的前端基于开关电容电路,将电容值转换为与电容有关的电荷。两个传感器共用一个2阶Δ-Σ模数转换器,以减小芯片面积。测试结果表明,在-55℃125℃范围内,温度传感器的准确度达到0.2℃(3σ);在03.8pF的范围内,电容传感器每一次测量的FOM值可达0.76pJ。整个芯片面积为0.2mm^2,供电电压为1.8V,电流为4.6μA。

A combined temperature and capacitance sensor interface was designed in the NXP 0.16μm CMOS process.The temperature-sensing front-end was based on the temperature dependency of bipolar transistors,and it translated the temperature into voltage.The capacitance sensor was based on switched-capacitor circuits,and it translated the capacitance into charge domain.The two sensors shared one 2nd-orderΔ-Σ ADC to reduce the chip area.The measured results showed that the temperature sensor had achieved 0.2℃（3σ） inaccuracy within a temperature range of -55℃ to 125℃,and the capacitance sensor had achieved 0.76 pJ FOM within an input range of 0 to 3.8 pF.The chip occupied 0.2 mm-2 area and drew 4.6μA current from a 1.8 V voltage supply.