Clock instantaneous temperature-rate-of-change measurement
Techniques described herein address these and other issues by utilizing two or more sensors to take temperature measurements from which a temperature-differential or instantaneous temperature rate-of-change, can be determined. In turn, this can be used to make a highly accurate model of the relationship between the temperature, temperature-differential, and clock circuitry frequency, to accurately estimate the frequency rate-of-change for frequency correction/compensation.
1. A system for determining a frequency rate-of-change of clock circuitry, the system comprising:
an assembly of electrical components on a substrate, the assembly of electrical components comprising:
the clock circuitry;
a heat source; and
a plurality of thermal sensors, wherein:
a first thermal sensor of the plurality of thermal sensors is on the substrate on a proximal side of the clock circuitry, relative to the heat source; and
a second thermal sensor of the plurality of thermal sensors is on the substrate on a distal side of the clock circuitry, relative to the heat source; and
a processing unit communicatively coupled with the first thermal sensor, the second thermal sensor, and the clock circuitry, wherein the processing unit is configured to:
determine a temperature-differential based on temperature measurements from each of the first thermal sensor and the second thermal sensor; and
determine a frequency rate-of-change of the clock circuitry, based at least in part on the determined temperature-differential.
2. The system of claim 1 , wherein the processing unit is further configured to:
determine a frequency of the clock circuitry, based at least in part on the determined temperature-differential; and
responsive to determining the frequency of the clock circuitry, output information indicative of the determined frequency.
3. The system of claim 1 , wherein the clock circuitry comprises a crystal oscillator (XO) circuit.
4. The system of claim 1 , wherein the assembly of electrical components further comprises a second heat source, and wherein the plurality of thermal sensors comprises more than two thermal sensors.
5. The system of claim 1 , wherein the heat source comprises a Power Management Integrated Circuit (PMIC).
6. The system of claim 1 , wherein the clock circuitry comprises an integrated circuit coupled to the substrate.
7. The system of claim 1 , wherein the clock circuitry, the heat source, the first thermal sensor, and the second thermal sensor are substantially aligned along a common axis.
8. The system of claim 1 , wherein determining the frequency rate-of-change of the clock circuitry comprises using a model having a set of parameters, and wherein the processing unit is further configured to determine the set of parameters based on:
a plurality of additional temperature measurements from each of the first thermal sensor and the second thermal sensor, and
a frequency reference.
9. The system of claim 8 , wherein the processing unit is configured to determine the set of parameters using an Extended Common Filter (EKF).
10. The system of claim 8 , wherein the frequency reference comprises a frequency estimator of a Global Navigation Satellite System (GNSS) or a Wireless Wide Area Network (WWAN).
11. A method of determining a clock frequency rate-of-change of clock circuitry, the method comprising:
obtaining a temperature measurement from each of a first thermal sensor and a second thermal sensor, wherein:
the first thermal sensor is on a substrate on a proximal side of the clock circuitry, relative to a heat source; and
the second thermal sensor is on the substrate on a distal side of the clock circuitry, relative to the heat source;
determining a temperature-differential based on the temperature measurement from each of the first thermal sensor and the second thermal sensor; and
determining a frequency rate-of-change of the clock circuitry based at least in part on the determined temperature-differential.
12. The method of claim 11 , further comprising:
determining a frequency of the clock circuitry, based at least in part on the determined temperature-differential; and
responsive to determining the frequency of the clock circuitry, outputting information indicative of the determined frequency.
13. The method of claim 11 , wherein the clock circuitry comprises a crystal oscillator (XO) circuit.
14. The method of claim 11 , wherein the heat source comprises a Power Management Integrated Circuit (PMIC).
15. The method of claim 11 , wherein the clock circuitry comprises an integrated circuit coupled to the substrate.
16. The method of claim 11 , wherein the clock circuitry, the heat source, the first thermal sensor, and the second thermal sensor are substantially aligned along a common axis.
17. The method of claim 11 , wherein determining the frequency rate-of-change of the clock circuitry comprises using a model having a set of parameters, and wherein the method further comprises determining the set of parameters based on:
a plurality of additional temperature measurements from each of the first thermal sensor and the second thermal sensor, and
a frequency reference.
18. The method of claim 17 , further comprising determining the set of parameters using an Extended Common Filter (EKF).
19. The method of claim 17 , wherein the frequency reference comprises a frequency estimator of a Global Navigation Satellite System (GNSS) or a Wireless Wide Area Network (WWAN).
20. A device comprising:
means for obtaining a temperature measurement from each of a first thermal sensing means and a second thermal sensing means, wherein:
the first thermal sensing means is on a substrate on a proximal side of clock circuitry, relative to a heat source; and
the second thermal sensing means is on the substrate on a distal side of the clock circuitry, relative to the heat source;
means for determining a temperature-differential based on the temperature measurement from each of the first thermal sensing means and the second thermal sensing means; and
means for determining a frequency rate-of-change of the clock circuitry based at least in part on the determined temperature-differential.
21. The device of claim 20 , further comprising:
means for determining a frequency of the clock circuitry, based at least in part on the determined temperature-differential; and
means for outputting information indicative of the determined frequency in response to determining the frequency of the clock circuitry.
22. The device of claim 20 , wherein the clock circuitry comprises a crystal oscillator (XO) circuit.
23. The device of claim 20 , wherein the heat source comprises a Power Management Integrated Circuit (PMIC).
24. The device of claim 20 , wherein the clock circuitry, the heat source, the first thermal sensing means, and the second thermal sensing means are substantially aligned along a common axis.
25. The device of claim 20 , wherein the means for determining the frequency rate-of-change of the clock circuitry comprises means for using a model having a set of parameters, and wherein the device further comprises means for determining the set of parameters based on:
a plurality of additional temperature measurements from each of the first thermal sensing means and the second thermal sensing means, and
a frequency reference.
26. A non-transitory computer-readable medium having instructions embedded thereon that, when executed by one or more processing units, cause the one or more processing units to:
obtain a temperature measurement from each of a first thermal sensor and a second thermal sensor, wherein:
the first thermal sensor is on a substrate on a proximal side of clock circuitry, relative to a heat source; and
the second thermal sensor is on the substrate on a distal side of the clock circuitry, relative to the heat source;
determine a temperature-differential based on the temperature measurement from each of the first thermal sensor and the second thermal sensor; and
determine a frequency rate-of-change of the clock circuitry based at least in part on the determined temperature-differential.
27. The non-transitory computer-readable medium of claim 26 , wherein the instructions, when executed by the one or more processing units, further cause the one or more processing units to:
determine a frequency of the clock circuitry, based at least in part on the determined temperature-differential; and
output information indicative of the determined frequency in response to determining the frequency of the clock circuitry.