Quantifying a difference between nodal voltages

• US 20030155903A1
• Filed: 02/19/2002
• Published: 08/21/2003
• Est. Priority Date: 02/19/2002
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Liu, Dean, Gauthier, Claude, Gold, Spencer, Amick, Brian, Zarrineh, Kamran, Trivedi, Pradeep
• Granted Patent: US 6,806,698 B2
• Time in Patent Office: Days
• US Class Current: 324/76.41
• CPC Class Codes: G01K 7/01 using semiconducting elements having PN junctions G01K7/02, G01K7/16, G01K7/30 take precedence
• CPC Class Codes: G01K 7/32 using change of resonant frequency of a crystal
• CPC Class Codes: H03M 1/0621 with auxiliary conversion of a value corresponding to the physical parameter(s) to be compensated for
• CPC Class Codes: H03M 1/60 with intermediate conversion to frequency of pulses

Abstract

A method and apparatus that uses the difference between two nodal voltages, such as a temperature-independent voltage and a temperature-dependent voltage, to determine the actual temperature at a point on an integrated circuit is provided. Further, a method and apparatus that converts a difference between nodal voltages in an integrated circuit from an analog to a digital quantity on the integrated circuit such that the difference in voltage may be used by an on-chip digital system is provided. Further, a method and apparatus for quantifying a difference in voltage between a first node and a second node of a temperature sensor is provided.

Claims

1. An apparatus for quantifying a difference in voltage between a temperature-independent voltage and a temperature-dependent voltage generated by a voltage generator, comprising:

a first oscillator that inputs the temperature-independent voltage, wherein the first oscillator generates a first oscillating frequency based on the temperature-dependent voltage;

a second oscillator that inputs the temperature-dependent voltage, wherein the second oscillator generates a second oscillating frequency based on the temperature-dependent voltage; and

a comparator that compares the first oscillating frequency and the second oscillating frequency and generates a digital word representative of a difference between the first oscillating frequency and the second oscillating frequency.

2. The apparatus of claim 1, wherein the first oscillating frequency oscillates at a higher frequency than the second oscillating frequency.

3. The apparatus of claim 1, wherein the second oscillating frequency is dependent on a temperature in the voltage generator.

4. The apparatus of claim 3, wherein the first oscillating frequency is substantially independent of the temperature in the voltage generator.

5. An apparatus for quantifying a difference in voltage between a first nodal voltage and a second nodal voltage generated by a voltage generator, comprising:

means for generating a first oscillating frequency based on the first nodal voltage;

means for generating a second oscillating frequency based on the second nodal voltage; and

means for generating a digital word representative of a comparison of the first and second oscillating frequencies.

6. The apparatus of claim 5, further comprising:

means for generating a first quantity based on the first nodal voltage;

means for generating a second quantity in relation to the first binary quantity.

7. The apparatus of claim 6, wherein the second quantity is based on the second nodal voltage.

8. The apparatus of claim 7, wherein the digital word is based on the second quantity.

9. A method for quantifying a difference in voltage between a first nodal voltage and a second nodal voltage generated by a voltage generator, comprising:

generating a first oscillating frequency based on the first nodal voltage, wherein the first oscillating frequency is generated with a first oscillator;

generating a second oscillating frequency based on the second nodal voltage, wherein the second oscillating frequency is generated with a second oscillator; and

generating a digital word in relation to the first and second oscillating frequencies, wherein the digital word is generated with a comparator.

10. The method of claim 9, further comprising:

generating a first quantity based on the first oscillating frequency, wherein the first quantity is generated with the comparator;

generating a second quantity in relation to the first quantity, wherein the second quantity is generated with the comparator.

11. The method of claim 10, wherein the second quantity is based on the second oscillating frequency.

12. The method of claim 10, wherein the digital word is based on the second quantity.

13. The method of claim 10, wherein the second quantity is generated by counting frequency pulses in the second oscillating frequency during a fixed timeslot.

14. The method of claim 10, wherein the first quantity is generated by counting frequency pulses in the first oscillating frequency during a fixed timeslot.

15. The method of claim 14, wherein the second quantity is generated by counting frequency pulses in the second oscillating frequency during the fixed timeslot.

16. The method of claim 10, wherein the second quantity is generated by counting frequency pulses in the second oscillating frequency during a variable timeslot.

17. The method of claim 10, wherein the first quantity is generated by counting frequency pulses in the first oscillating frequency during a variable timeslot.

18. The method of claim 17, wherein the second quantity is generated by counting frequency pulses in the second oscillating frequency during the variable timeslot.