Study Of Digital Temperature Sensor Based On CMOS Technology

When the high complete chip is working it will lead to local overheating which can deteriorate the performance of the circuit and shorten the life of the chip.So the real-time monitoring of the temperature in the chip becomes important.Aiming at the project requirement,this paper designs a temperature sensor which can integrate into the high performance inertial sensor.Realizes the calibration of data at different temperatures at the system level,thus ensuring the temperature stability of high performance inertial sensor.This requires real-time monitoring of the internal temperature of the chip.The digital output temperature sensor of this paper is composed of temperature-test part and analog-to-digital converter.The temperature-test part is designed based on high-linearity and controllability of thermal voltage formed by make difference from two PN junction voltage with different current density,In order to improve the stability of the circuit,adding a high gain amplifier in the circuit makes the circuit work under the condition of deep negative feedback.After the circuit simulation satisfies the design requirement,the part of the temperature measurement is carried out.Then the analog output temperature sensor is tested for high and low temperature,sensor can work stable from-45 ? to 85 ?.According to the simulated output part of the test case,a low speed,small area,low power consumption,effective bit more than 6 bits of the dual-integral ADC.In order to facilitate testing,an output level module is added to the ADC to achieve the 3.3 V level serial output.After fabrication,two samples is tested in room temperature and different temperaturet.The test results shows that ADC effective potential reaches 7 bits,the overall power dissipation in 10 m W.Analog output part can work stable from-45 ? to 85 ? that meets the design indicators.The effective temperature range of analog output can reach-86 ? ~160 ?.The sensor can integrate into high performance inertial sensor ASIC and realize real-time temperature monitoring.