Parameters Identification of Embedded PTAT Temperature Sensors for CMOS Circuits MIXDES '07. 14th International Conference on Mixed Design of Integrated Circuits and Systems, 2007 IEEE Speaker ： Shun-He Huang

Outline Introduction PTAT circuit Layout of the test chip Simulations and Measurements Conclusion

Introduction The temperature sensors have become common elements in wide range of modern integrated circuits. The main parameters of temperature sensors are: temperature range, sensitivity, output range, linearity, accuracy. This paper describe the PTAT (proportional to absolute temperature) temperature sensors that are implemented in the test chip and dedicated to CMOS integrated circuits.

PTAT circuit △ V BE =V BE1 -V BE2 =V T ln(N) =KT/q*ln(N) I 2 =V T *ln(N)/R 1 I PTAT =I 5 =W 5 /W 4 *I 2

Parameters of the PTAT sensor

Layout of the test chip The locations and orientation of the test temperature sensors

Thermal chamber The photo of the device Enlarged test chip in the chamber

Simulation and Measurement The test chip suppy voltage is 5V. The measurements were performed in a thermal chamber for the temperature range of K. The achieved sensitivities of the temperature sensors are within following limits 3.44 to 4.82 mV/K.

Temperature vs. output voltage of the PTAT_1 sensor Output voltage vs. temperature of the PTAT_1 sensor

Temperature vs. output voltage of the sensors, which have orientation O1 Temperature vs. output voltage of the sensors, which have orientation O2

Temperature vs. output voltage of the sensors, which have orientation O3 Temperature vs. output voltage of the sensors, which have orientation O4

Exemplary results of temperature measurements for the PTAT_1 sensor

Conclusion The presented temperature sensors are one of the most important elements that are implemented in the test chip. Their parameters such as linearity and sensitivity are good enough to dedicated purposes. The self-heating effect and electro-thermal interactions also will be using this chip.