On-Chip Circuit and Method for Accurately Measuring Die Temperature of an Integrated Circuit

Patent metadata

Field	Value
Publication number	US-2016178450-A1
Application number	US-201514925703-A
Country	US
Kind code	A1
Filing date	Oct 28, 2015
Priority date	Dec 23, 2014
Publication date	Jun 23, 2016
Grant date	—

Abstract

An integrated circuit and method are provided for accurately measuring the temperature of a die of the integrated circuit. Pairs of diodes are driven with different currents in order to generate a series of thermal voltages. The ADC measures the series of thermal voltages against an external reference voltage. Based on these thermal voltage measurements, the ADC calculates the die temperature. The different currents used to generate the series of thermal voltages are selected at specific ratios to each other in order to promote the ability of the ability of the ADC to calculate the die temperature using standard components and logic of an ADC. These thermal voltages are generated and measured using integrated components of the die for which a temperature measurement is being provided, thus reducing several sources of inaccuracies in conventional die temperature measurement techniques. Addition embodiments are provided for detecting defective diodes based on comparisons of the thermal voltage outputs.

First claim

What is claimed is:

1 . A temperature sensor integrated circuit comprising:
a die; a thermal voltage source operable to generate pairs of the thermal voltages, wherein each of the pair of thermal voltages varies with the temperature of the die, and wherein the thermal voltage source is a component of the die; and an ADC operable to receive an external reference voltage provided as an input to the temperature sensor integrated circuit and further operable to receive the pairs of thermal voltages; wherein the ADC is further operable to calculate a PTAT voltage based on pairs of thermal voltages and an external reference voltage, and wherein the ADC is a component of the die.

2 . The temperature sensor integrated circuit of claim 1 , wherein the thermal voltage source is comprised of a first pair of diodes configured to generate a first pair of thermal voltage outputs.

3 . The temperature sensor integrated circuit of claim 2 , wherein the thermal voltage source is further comprised of a second pair of diodes configured to generate a second pair of thermal voltage outputs.

4 . The temperature sensor integrated circuit of claim 3 , wherein the ADC is further operable to calculate the difference between the first pair of thermal voltages or the difference between the second pair of thermal voltages.

5 . The temperature sensor integrated circuit of claim 1 , wherein the pairs of thermal voltages are generated using three currents of three different current levels.

6 . The temperature sensor integrated circuit of claim 5 , wherein the ratios between each of the three different currents levels are selected such that the ADC calculates the PTAT voltage using addition and subtraction operations.

7 . The temperature sensor integrated circuit of claim 3 , wherein the first pair of diodes comprises two matching diodes of a first type and the second pair of diodes comprise two diodes of a second type.

8 . The temperature sensor integrated circuit of claim 2 , wherein a pair of diagnostic thermal voltages is generated by forcing the same current onto both diodes from the first pair of diodes, and wherein the diagnostic pair of thermal voltages is used to detect defects with the first pair of diodes.

9 . The temperature sensor integrated circuit of claim 7 , wherein the first pair of diodes generate a first thermal voltage and the second pair of diodes generate a second thermal voltage, and wherein a discrepancy in the first thermal voltage and the second thermal voltage is used to detect a discrepancy in an ideality factor of a diode from the first pair of diodes or the second pair of diodes.

10 . The temperature sensor integrated circuit of claim 1 , wherein the thermal voltage inputs to the ADC are generated using a force sense connection.

11 . A method for calculating the temperature of an integrated circuit, the method comprising generating pairs of thermal voltages by forcing different currents into pairs of thermal voltage components, wherein each of the pair of thermal voltages varies with the temperature of the die, and wherein the thermal voltages are generated by components of the integrated circuit;
receiving an external reference voltage provided as an input to the integrated circuit; and calculating a PTAT voltage based on the generated pairs of thermal voltages and the external reference voltage, wherein the PTAT voltage is calculated by a component of the integrated circuit.

12 . The method of claim 11 , wherein the pairs of thermal voltages are generated using a first pair of diodes configured to generate a first pair of thermal voltage outputs.

13 . The method of claim 12 , wherein the pairs of thermal voltages are further generated using a second pair of diodes configured to generate a second pair of thermal voltage outputs.

14 . The method of claim 13 , the method further comprising:
calculating the difference between the first pair of thermal voltages or the difference between the second pair of thermal voltages.

15 . The method of claim 11 , wherein the pairs of thermal voltages are generated using three currents of three different current levels.

16 . The method of claim 14 , wherein the ratios between each of the three different currents levels are selected such that the PTAT voltage is calculated using ADC addition and subtraction operations.

17 . The method of claim 13 , wherein the first pair of diodes comprises two matching diodes of a first type and the second pair of diodes comprise two diodes of a second type.

18 . The method of claim 12 , the method further comprising:
generating a pair of diagnostic thermal voltages by forcing the same current onto both diodes from the first pair of diodes, wherein the diagnostic pair of thermal voltages is used to detect defects with the first pair of diodes.

19 . The method of claim 17 , further comprising:
comparing a first thermal voltage generated by the first pair of diodes and a second thermal voltage generated by the second pair of diodes to identify a discrepancy in an ideality factor of a diode from the first pair of diodes or the second pair of diodes.

20 . The method of claim 11 , wherein the thermal voltage inputs are generated using a force sense connection.

Assignees

• Texas Instruments Inc

Inventors

• Trifonov Dimitar
• Karaki Habib Sami

Classifications

• G01K7/01 Primary

  using semiconducting elements having PN junctions (G01K7/02, G01K7/16, G01K7/30 take precedence) · CPC title

• G01K7/16 Primary

  using resistive elements · CPC title