Determining rate of change in temperature measurements
A temperature sensor device has a digital interface with a first memory storing a current temperature value which can be read through the digital interface and a second memory storing a rate of temperature change value which can be read through the digital interface. Such a temperature sensor can be preferably used in a system with a cooling fan and a processor coupled with the digital interface of the temperature sensor. The processor is operable to control the cooling fan based on temperature measurement values and the rate of change in temperature retrieved from the temperature sensor through the digital interface.
1. A temperature sensor device comprising:
a digital interface;
a first memory storing a current temperature value which can be read through said digital interface;
a second memory storing a rate of temperature change value which can be read through said digital interface;
a processor coupled with the digital interface, the processor configured to:
issue control signals for cooling based on the current temperature value and the rate of temperature change value;
identify whether a slope direction changes and store a change of the slope direction in the second memory; and
identify a plurality of slope direction changes within a measurement interval;
wherein the control signals include the identification of the plurality of slope direction changes.
2. The temperature sensor according to claim 1 , wherein the second memory stores a result of a calculation performed within the temperature sensor using a plurality of sequential temperature measurement samples defining a measurement interval.
3. The temperature sensor according to claim 2 , wherein the number of samples is programmable.
4. The temperature sensor according to claim 2 , wherein the rate of temperature change value is calculated by:
Δ
T
Δ
t
=
[
T
(
t
max
)
-
T
(
t
0
)
]
*
gain
samples
wherein:
T(t max ) is a temperature at an end of the measurement interval;
T(t 0 ) is a temperature at a beginning of the measurement interval;
gain is a factor to be applied to a temperature difference; and
samples are a number of samples.
5. The temperature sensor according to claim 1 , wherein the second memory stores the number of times a slope direction changes within the measurement interval.
6. The temperature sensor according to claim 1 , further comprising an external alert output connection controlled by the rate of temperature change value.
7. The temperature sensor according to claim 1 , wherein the first memory stores an average temperature value.
8. The temperature sensor according to claim 7 , wherein a number of temperature values used to calculate the average temperature value is programmable.
9. The temperature sensor according to claim 1 , wherein the second memory is a register accessible by the digital interface.
10. The temperature sensor according to claim 1 , wherein the second memory is provided by a plurality of registers.
11. The temperature sensor device of claim 1 , wherein the processor is further configured to record a maximum or minimum for a time at which the slope direction changes.
12. An electronic device comprising:
a temperature sensor configured to determine a rate of change in a measured temperature which can be accessed through a digital interface;
a cooling fan; and
a processor coupled with the digital interface of the temperature sensor and being operable to:
control said cooling fan based on temperature measurement values and said rate of change in temperature retrieved from said temperature sensor through the digital interface;
identify whether a slope direction changes and store a change of the slope direction through the digital interface; and
identify a plurality of slope direction changes within a measurement interval;
wherein the control signals include the identification of the plurality of slope direction changes.
13. A method for providing temperature data by a temperature sensor device comprising a digital interface, comprising storing a current temperature value in a first memory which can be read through said digital interface;
storing a rate of temperature change value in a second memory which can be read through said digital interface;
issuing control signals for cooling based on the current temperature value and the rate of temperature change value;
identifying whether a slope direction changes and storing the slope direction change in the second memory; and
identifying a plurality of slope direction changes within a measurement interval;
wherein the control signals include the identification of the control signals based upon the plurality of slope direction changes.
14. The method according to claim 13 , wherein the second memory stores a calculation performed within the temperature sensor using a plurality of sequential temperature measurement samples defining a measurement interval.
15. The method according to claim 14 , wherein the number of samples is programmable.
16. The method according to claim 14 , wherein the rate of temperature change value is calculated by:
Δ
T
Δ
t
=
[
T
(
t
max
)
-
T
(
t
0
)
]
*
gain
samples
wherein:
T(t max ) is a temperature at an end of the measurement interval;
T(t 0 ) is a temperature at a beginning of the measurement interval;
gain is a factor to be applied to a temperature difference; and
samples are a number of samples.
17. The method according to claim 13 , wherein the second memory further stores whether a slope direction changes.
18. The method according to claim 17 , wherein the second memory stores the number of times a slope direction changes within the measurement interval.
19. The method according to claim 13 , further comprising the step of outputting a signal through an external alert output connection depending on the rate of temperature change value.
20. The method according to claim 13 , wherein the first memory is a memory block and also stores an average temperature value.
21. The method according to claim 20 , wherein a number of temperature values used to calculate the average temperature value is programmable.
22. The method according to claim 13 , wherein the second memory is a register accessible by the digital interface.
23. The method according to claim 13 , wherein the second memory is provided by a plurality of registers forming a register block.
24. A method for controlling a temperature in a system comprising a temperature sensor configured to determine a rate of change in a measured temperature which can be accessed through a digital interface, a cooling fan, and a processor coupled with the digital interface of the temperature sensor, the method comprising:
determining a rate of change of a measured temperature;
controlling the cooling fan based on temperature measurement values and said rate of change in the temperature;
identifying whether a slope direction changes and storing the slope direction change in a memory through the digital interface; and
identifying a plurality of slope direction changes within a measurement interval;
wherein the control signals include the identification of the plurality of slope direction changes.