DYNAMIC VOLTAGE REFERENCE FOR SAMPLING DELTA BASED TEMPERATURE SENSOR

• US 20130120930A1
• Filed: 11/15/2011
• Published: 05/16/2013
• Est. Priority Date: 11/15/2011
• Status: Active Grant

• Current Assignee: ATI Technologies ULC (Advanced Micro Devices, Inc.)
• Original Assignee: Kristina Au
• Inventors: Temkine, Grigori, Chekmazov, Filipp, Edelshteyn, Paul, Drapkin, Oleg, Au, Kristina
• Granted Patent: US 9,347,836 B2
• Time in Patent Office: Days
• US Class Current: 361/679.47
• CPC Class Codes: G01K 7/01 using semiconducting elements having PN junctions G01K7/02, G01K7/16, G01K7/30 take precedence
• CPC Class Codes: G06F 1/206 comprising thermal management

Abstract

A system and method for measuring integrated circuit (IC) temperature. An integrated circuit (IC) includes a thermal sensor and data processing circuitry. The thermal sensor utilizes switched currents provided to a reference diode and a thermal diode. The ratios of the currents provided to each of these diodes may be chosen to provide a given delta value between the resulting sampled diode voltages. At a later time, a different ratio of currents may be provided to each of these diodes to provide a second given delta value between the resulting sampled diode voltages. A differential amplifier within the data processing circuitry may receive the analog sampled voltages and determine the delta values. Other components within the data processing circuitry may at least digitize and store one or both of the delta values. A difference between the digitized delta values may calculated and used to determine an IC temperature digitized code.

Claims

1. A temperature measurement circuit comprising:

a thermal sensor circuit configured to generate a first reference voltage, a first voltage, a second reference voltage, and a second voltage; and

circuitry configured to;

determine a first difference between the first voltage and the first reference voltage;

determine a second difference between the second voltage and the second reference voltage; and

calculate a temperature value based at least in part on a difference between the first difference and the second difference.

2. The temperature measurement circuit as recited in claim 1, wherein the thermal sensor circuit is further configured to:

generate the first voltage and the first reference voltage at a given area of an integrated circuit at a first point-in-time; and

generate the second voltage and the second reference voltage at the given area at a second point-in-time after the first point-in-time.

3. The temperature measurement circuit as recited in claim 2, wherein the thermal sensor circuit is further configured to provide a first current density through a thermal diode and a reference current density through a reference diode at the first point-in-time to generate each of the first voltage and the first reference voltage, respectively.

4. The temperature measurement circuit as recited in claim 3, wherein the thermal sensor circuit is further configured to provide a second current density through the thermal diode and the reference current density through the reference diode at the second point-in-time to generate each of the second voltage and the second reference voltage, respectively.

5. The temperature measurement circuit as recited in claim 4, wherein a first ratio of the reference current density to the first current density provided at the first point-in-time is a square root of a second ratio of the second current density provided at the second point-in-time to the first current density.

6. The temperature measurement circuit as recited in claim 5, wherein a ratio of the reference current density to the second current density provided at the second point-in-time is an inverse of the first ratio.

7. The temperature measurement circuit as recited in claim 5, wherein the second diode is smaller than the first diode.

8. The temperature measurement circuit as recited in claim 5, wherein the circuitry is further configured to send the calculated temperature value to a thermal cooling controller configured to perform at least one of the following:

select a lower performance-power state and increase a speed of a fan.

9. A method comprising:

generating a first reference voltage, a first voltage, a second reference voltage, and a second voltage;

determining a first difference between the first voltage and the first reference voltage;

determining a second difference between the second voltage and the second reference voltage; and

calculating a temperature value based at least in part on a difference between the first difference and the second difference.

10. The method as recited in claim 9, further comprising:

generating the first voltage and the first reference voltage at a given area of an integrated circuit at a first point-in-time; and

generating the second voltage and the second reference voltage at the given area at a second point-in-time after the first point-in-time.

11. The method as recited in claim 10, further comprising providing a first current density through a thermal diode and a reference current density through a reference diode at the first point-in-time to generate each of the first voltage and the first reference voltage, respectively.

12. The method as recited in claim 11, further comprising providing a second current density through the thermal diode and the reference current density through the reference diode at the second point-in-time to generate each of the second voltage and the second reference voltage, respectively.

13. The method as recited in claim 12, wherein a first ratio of the reference current density to the first current density provided at the first point-in-time is a square root of a second ratio of the second current density provided at the second point-in-time to the first current density.

14. The method as recited in claim 13, wherein a ratio of the reference current density to the second current density provided at the second point-in-time is an inverse of the first ratio.

15. The method as recited in claim 12, wherein the second diode is smaller than the first diode.

16. The method as recited in claim 14, further comprising sending the calculated temperature value to a thermal cooling controller configured to perform at least one of the following:

select a lower performance-power state and increase a speed of a fan.

17. A computer system comprising:

an integrated circuit (IC) comprising an on-die temperature measurement circuit configured to;

generate each of a first reference voltage, a first voltage, a second reference voltage, and a second voltage;

determine a first difference between the first voltage and the first reference voltage;

determine a second difference between the second voltage and the second reference voltage; and

calculate a temperature value based at least in part on a difference between the first difference and the second difference; and

a thermal cooling controller configured to;

receive the calculated temperature value; and

change a condition of operation for the IC in response to determining the temperature value exceeds a given threshold.

18. The computer system as recited in claim 17, wherein the temperature measurement circuit is further configured to:

generate the first voltage and the first reference voltage at a given area of an integrated circuit at a first point-in-time; and

generate the second voltage and the second reference voltage at the given area at a second point-in-time after the first point-in-time.

19. The computer system as recited in claim 18, wherein the temperature measurement circuit is further configured to:

provide a first current density through a thermal diode and a reference current density through a reference diode at the first point-in-time to generate each of the first voltage and the first reference voltage, respectively; and

provide a second current density through the thermal diode and the reference current density through the reference diode at the second point-in-time to generate each of the second voltage and the second reference voltage, respectively.

20. The computer system as recited in claim 19, wherein changing the condition of operation by the thermal cooling controller comprises at least one of the following:

selecting a lower performance-power state and increasing a speed of a fan.

21. A thermal sensing circuit comprising:

a first p-n junction comprising a first cathode coupled to a first voltage reference configured to generate a reference forward voltage responsive to a reference current flowing through the first p-n junction;

a second p-n junction comprising a second cathode coupled to the first voltage reference configured to;

generate a first forward voltage responsive to a first test current flowing through the second p-n junction; and

generate a second forward voltage responsive to a second test current flowing through the second p-n junction;

wherein an indication of a substrate temperature is provided by (i) a relationship between the first forward voltage and the reference forward voltage, and (ii) a relationship between the second forward voltage and the reference voltage.