MULTIPLE SENSOR THERMAL MANAGEMENT FOR ELECTRONIC DEVICES

• US 20110096809A1
• Filed: 01/05/2011
• Published: 04/28/2011
• Est. Priority Date: 08/30/2006
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Campos, Marcelo de Paula, Silva Junior, Edevaldo Pereira da, Nascimento, Ivan Carlos Ribeiro do
• Granted Patent: US 8,398,304 B2
• Time in Patent Office: Days
• US Class Current: 374/178
• CPC Class Codes: G01K 3/005 Circuits arrangements for indicating a predetermined temperature fire detection G08B17/00
• 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
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/324 by lowering clock frequency
• CPC Class Codes: G06F 1/3287 by switching off individual functional units in the computer system
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A device includes a current source circuit to separately provide a first current and a second current and a thermal detection device coupleable to the output of the current source circuit. The device further includes a voltage detection circuit to provide a first indicator of a first voltage representative of a voltage at the thermal detection device in response to the second current and a second indicator of a second voltage representative of a voltage difference between the voltage at the thermal detection device in response to the second current and a voltage at the voltage detection device in response to the first current. The device further includes a temperature detection circuit to provide an over-temperature indicator based on the first indicator and the second indicator, wherein an operation of a circuit component of the device can be adjusted based on the over-temperature indicator.

Claims

1. A device comprising:

a current source circuit having an output to separately provide a first current and a second current;

a first thermal detection device disposed at a first location of the device, the first thermal detection device coupleable to the output of the current source circuit;

a voltage detection circuit comprising an input coupleable to the first thermal detection device and an output to provide;

a first indicator of a first voltage representative of a voltage at the first thermal detection device in response to the second current; and

a second indicator of a second voltage representative of a voltage difference between the voltage at the first thermal detection device in response to the second current and a voltage at the first thermal detection device in response to the first current; and

a temperature detection circuit having an input coupled to the output of the voltage detection circuit and an output to provide a first over-temperature indicator based on the first indicator and the second indicator.

2. The device of claim 1, wherein the temperature detection circuit is configured to:

provide a first state indicator in response to the second voltage being greater than the first voltage; and

provide a second state indicator in response to the second voltage being less than the first voltage.

3. The device of claim 1, wherein the voltage detection circuit comprises at least one of:

an attenuation circuit having an input to receive the voltage at the first thermal detection device in response to the second current and an output to provide the first voltage, wherein an attenuation factor of the attenuation circuit is programmable; and

an amplification circuit having an input to receive the voltage difference and an output to provide the second voltage, wherein a gain factor of the amplification circuit is programmable.

4. The device of claim 1, further comprising:

a second thermal detection device disposed at a second location of the device, the second thermal detection device coupleable to the output of the current source circuit; and

wherein the input of the voltage detection circuit is coupleable to the second thermal detection device;

wherein the output of the voltage detection circuit further is to provide;

a third indicator of a third voltage representative of a voltage at the second thermal detection device in response to the second current; and

a fourth indicator of a fourth voltage representative of a difference between a voltage at the second thermal detection device in response to the second current and a voltage at the second thermal detection device in response to the first current; and

wherein the output of the over-temperature detection circuit further is to provide a second over-temperature indicator based on the third indicator and the fourth indicator.

5. The device of claim 4, wherein an operation of a second circuit component of the device is enabled or disabled based on the second over-temperature indicator

6. The device of claim 1, wherein the voltage detection circuit comprises:

a capacitive element having a first electrode and a second electrode, the first electrode coupleable to the first electrode of the first thermal detection device;

a transistor having a control electrode, a first current electrode coupled to the second electrode of the capacitive element and a second current electrode coupled to the first voltage reference; and

wherein the transistor is configured to be enabled when the current source circuit provides the first current and disabled when the current source provides the second current.

7. The device of claim 6, wherein the temperature detection circuit comprises:

a comparator circuit having a first input coupled to the first electrode of the capacitive element, a second input coupled to the second electrode of the capacitive element, and an output to provide an output voltage based on a comparison of the third voltage to the fourth voltage, wherein the output voltage is representative of the first over-temperature indicator.

8. The device of claim 1, wherein the first thermal detection device comprises a p-n junction.

9. The device of claim 8, wherein:

the p-n junction comprises a p-type region coupleable to the current source circuit via a first interconnect and a second interconnect and an n-type region coupleable to the current source circuit via a third interconnect, wherein a resistance of the third interconnect is substantially equal to a resistance of the second interconnect;

the current source circuit is configured to provide the first current to the p-type region via both the first electrode and the second electrode concurrent with a third current provided to the n-type region via the third electrode, wherein the third current is substantially equal to a current at the second electrode; and

the temperature detection circuit is coupleable to the second interconnect and the third interconnect, wherein the temperature detection circuit is configured to determine the first voltage and the second voltage via the second interconnect and the third interconnect.

10. The device of claim 1, wherein an operation of the first circuit component of the device is enabled or disabled based on the first over-temperature indicator.

11. The device of claim 1, wherein the device comprises an integrated circuit comprising the current source circuit, the first thermal detection device, the voltage detection circuit, and the temperature detection circuit.

12. A device comprising:

a first thermal detection device disposed at a first location of the device to receive a first current and a second current;

a voltage detection circuit comprising an input coupleable to the first thermal detection device and an output to provide;

a first indicator of a first voltage representative of a voltage at the first thermal detection device in response to the second current; and

a second indicator of a second voltage representative of a voltage difference between the voltage at the first thermal detection device in response to the second current and a voltage at the first thermal detection device in response to the first current; and

a temperature detection circuit having an input coupled to the output of the voltage detection circuit and an output to provide a first over-temperature indicator based on the first indicator and the second indicator.

13. The device of claim 12, wherein the temperature detection circuit is configured to:

provide a first state indicator in response to the second voltage being greater than the first voltage; and

provide a second state indicator in response to the second voltage being less than the first voltage.

14. The device of claim 12, wherein the voltage detection circuit comprises at least one of:

an attenuation circuit having an input to receive the voltage at the first thermal detection device in response to the second current and an output to provide the first voltage, wherein an attenuation factor of the attenuation circuit is programmable; and

an amplification circuit having an input to receive the voltage difference and an output to provide the second voltage, wherein a gain factor of the amplification circuit is programmable.

15. The device of claim 12, wherein the voltage detection circuit comprises:

a capacitive element having a first electrode and a second electrode, the first electrode coupleable to the first electrode of the first thermal detection device;

a transistor having a control electrode, a first current electrode coupled to the second electrode of the capacitive element and a second current electrode coupled to the first voltage reference; and

wherein the transistor is configured to be enabled when a current source circuit provides the first current and disabled when the current source provides the second current.

16. The device of claim 15, wherein the temperature detection circuit comprises:

a comparator circuit having a first input coupled to the first electrode of the capacitive element, a second input coupled to the second electrode of the capacitive element, and an output to provide an output voltage based on a comparison of the third voltage to the fourth voltage, wherein the output voltage is representative of the first over-temperature indicator.

17. The device of claim 12, wherein the first thermal detection device comprises a p-n junction.

18. The device of claim 17, wherein:

the p-n junction comprises a p-type region coupleable to a current source circuit via a first interconnect and a second interconnect and an n-type region coupleable to the current source circuit via a third interconnect, wherein a resistance of the third interconnect is substantially equal to a resistance of the second interconnect;

the current source circuit is configured to provide the first current to the p-type region via both the first electrode and the second electrode concurrent with a third current provided to the n-type region via the third electrode, wherein the third current is substantially equal to a current at the second electrode; and

the temperature detection circuit is coupleable to the second interconnect and the third interconnect, wherein the temperature detection circuit is configured to determine the first voltage and the second voltage via the second interconnect and the third interconnect.

19. The device of claim 12, wherein an operation of the first circuit component of the device is enabled or disabled based on the first over-temperature indicator.

20. A device comprising:

a current source circuit having an output to separately provide a first current and a second current;

a first thermal detection device disposed at a first location of the device, the first thermal detection device coupleable to the output of the current source circuit;

a voltage detection circuit comprising an input coupleable to the first thermal detection device and an output to provide;

a first indicator of a first voltage representative of a voltage at the first thermal detection device in response to the second current; and

a second indicator of a second voltage representative of a voltage difference between the voltage at the first thermal detection device in response to the second current and a voltage at the first thermal detection device in response to the first current;

a temperature detection circuit having an input coupled to the output of the voltage detection circuit and an output to provide a first over-temperature indicator based on the first indicator and the second indicator; and

an attenuation circuit having an input to receive the voltage at the first thermal detection device in response to the second current and an output to provide the first voltage, wherein an attenuation factor of the attenuation circuit is programmable.