Parameters Identification of Embedded PTAT Temperature Sensors for CMOS Circuits

MIXDES '07. 14th International Conference on Mixed Design of Integrated Circuits and Sys

tems, 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

△VBE=VBE1-VBE2

=VTln(N) =KT/q*ln(N)I2=VT*ln(N)/R1

IPTAT=I5 =W5/W4*I2

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 288-358 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 measurementsfor 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.