开关式低压CMOS温度传感器的设计与实现

Design and Implementation of the Switch Type and Low Voltage CMOS Temperature Sensor

介绍了一种基于0.18μm CMOS工艺,具有开关功能的低压集成温度传感器。该温度传感器利用半导体pn结的电流电压与温度有关的特性,获取双极晶体管基极-发射极电压差值ΔVBE,采用仪表放大器进行后级放大。仪表放大器由两个采用折叠式共源共栅结构,带有PD开关信号的运算放大器作为反馈系统,放大倍数为7。用ADE工具,对整个电路在工作电压1.8 V、偏置电流20μA下进行仿真,得到其精度为1.58 mV/℃,再在不同工艺角下进行仿真验证。版图总面积为320μm×280μm。该设计已经在一款数字视频芯片中得到实现,用于实时检测芯片温度。实际测试结果与模拟仿真结果基本相同。

A CMOS temperature sensor based on the 0.18 μm CMOS technology,which can be shut off easily was presented.Based on properties that the current and voltage of the semiconductor pn junction was related to the temperature,the design obtain the voltage difference of BJT＇s base-emitter and amplifies signals with an instrument amplifier.The instrument amplifier uses two folded-cascaded operational amplifiers,which contains a PD shut-off signal as the feedback system.The times of the instrument amplifier is 7.The simulation result from the ADE tools shows that the precision of the CMOS temperature sensor is 1.58 mV/℃,under the working condition of 1.8 V supply voltage and 20 μA offset current.The simulation was performed in different process corners to verify the design.The whole layout area is 320 μm×280 μm.The design is already used in a digital video process chip for monitoring the temperature.The reality results are almost the same with the circuit simulation.