Monitoring circuit

• US 6,810,338 B2
• Filed: 10/22/2001
• Issued: 10/26/2004
• Est. Priority Date: 10/23/2000
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Håkansson, Niclas, Edholm, Bengt, Ptasinski, Kristoffer, Mercke, Johan
• Primary Examiner(s): ASSOUAD, PATRICK J
• Application Number:
  US09/982,801
• Publication Number:
  US 20020047797A1
• Time in Patent Office: 1,100 Days
• Field of Search: 702/63, 320/137, 320/152, 320/162, 455/127.1, 455/572, 455/573
• US Class Current: 702/63
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm

Abstract

There is provided a monitoring device which can be used as a battery monitor in a mobile communications device, such as a mobile phone. The monitoring device includes output registers, from which parameter values can be read by a processor unit.

Advantageously, the device makes frequent measurements, and updates parameter values on the basis of those measurements. The updated stored parameter values can then be read by the processor. This has the advantage that the processor does not have to read a large number of values, in order to obtain the information required about the parameters. This therefore has the result that communications on the bus are reduced, and power consumption is reduced.

For example, the parameters may include a maximum battery voltage, a minimum battery voltage, and an average battery voltage, as well as parameters relating to the current supplied to the battery during charging.

Claims

1. A monitoring device, for allowing a processor to monitor a value of a parameter derived from an analog signal, the monitoring device comprising:

an analog-digital converter, for producing a digital signal corresponding to the analog signal, wherein said digital signal comprises a digital signal stream, corresponding to successive measured values of the parameter;

a logic unit, for obtaining at least one value of said parameter, based on the digital signal, said logic unit being adapted for updating the value of the or each parameter contained in the register as required in response to the digital signal stream; and

an output register, accessible by the processor unit, the register containing at least one said obtained value of said parameter derived from said digital signal stream.

2. A monitoring device as claimed in claim 1, wherein the monitoring device further comprises means for setting a threshold value for said parameter, and for sending a signal to said processor when a parameter value contained in the output register reaches the threshold value.

3. A monitoring device, as claimed in claim 1, wherein:

said monitoring device is adapted for connection to a battery; and

said parameter derived from said analog signal comprises a voltage supplied by the battery.

4. A monitoring device as claimed in claim 3, wherein the register contains the maximum value of the battery voltage supplied over a period since the register was last accessed by the processor.

5. A monitoring device as claimed in claim 3, wherein the register contains the minimum value of the battery voltage supplied over a period since the register was last accessed by the processor.

6. A monitoring device as claimed in claim 3, wherein the register contains the average value of the battery voltage supplied over a fixed period.

7. A monitoring device a claimed in claim 1, wherein:

said monitoring device is adapted for connection to a battery; and

said parameter derived from said analog signal comprises a charging current supplied to the battery.

8. A monitoring device as claimed in claim 7, wherein the register contains the maximum value of the charging current supplied over a period since the register was last accessed by the processor.

9. A monitoring device as claimed in claim 7, wherein the register contains the minimum value of the charging current supplied over a period since the register was last accessed by the processor.

10. A monitoring device as claimed in claim 7, wherein the register contains the average value of the charging current supplied over a period.

11. A mobile communications device, comprising a monitoring device as claimed in claim 7, wherein the processor is a processor of the mobile communication device.

12. A mobile communications device, comprising a monitoring device as claimed in claim 3, wherein the processor is a processor of the mobile communications device.

13. A mobile communications device as claimed in claim 12, wherein the register contains the maximum value of the battery voltage supplied over a period and the average value of the battery voltage supplied over a period.

14. A mobile communications device as claimed in claim 13, wherein the maximum value of the battery voltage supplied over a period is updated at a first rate, and the average value of the battery voltage supplied over a period is updated at a second rate slower than the first rate.

15. A mobile communications device as claimed in claim 13, which, in at least one mode of operation, produces an internal signal indicating that the device is transmitting, and wherein the stored maximum value of the battery voltage is updated at a first rate while said internal signal is being produced, and at a second lower rate while said internal signal is not being produced.

16. A mobile communications device as claimed in claim 12, wherein the register contains the minimum value of the battery voltage supplied over a period and the average value of the battery voltage supplied over a period.

17. A mobile communications device as claimed in claim 16, wherein the minimum value of the battery voltage supplied over a period is updated at a first rate, and the average value of the battery voltage supplied over a period is updated at a second rate slower than the first rate.

18. A mobile communications device as claimed in claim 16 , which, in at least one mode of operation, produces an internal signal indicating that the device is transmitting, and wherein the stored minimum value of the battery voltage is updated at a first rate while said internal signal is being produced, and at a second lower rate while said internal signal is not being produced.

19. A mobile communications device as claimed in claim 12, which, in at least one mode of operation, produces an internal signal indicating that the device is transmitting, and wherein the register contains a first minimum value of the battery voltage supplied over a period while said internal signal is being produced, and a second minimum value of the battery voltage supplied over a period while said internal signal is not being produced.

20. A monitoring device as claimed in claim 1, wherein:

said monitoring device is adapted for connection to a battery; and

said parameter derived from said analog signal comprises a temperature.

21. A monitoring device as claimed in claim 20, wherein the register contains the maximum value of the temperature supplied over a period since the register was last accessed by the processor.

22. A monitoring device as claimed in claim 20, wherein the register contains the minimum value of the temperature supplied over a period since the register was last accessed by the processor.

23. A monitoring device as claimed in claim 20, wherein the register contains the average value of the temperature supplied over a fixed period.

38. A monitoring device as claimed in claim 1, wherein said digital signal comprises a digital signal stream, and said logic unit adapted for updating the value of the or each parameter contained in the register as required in response to the digital stream.

39. A monitoring device as claimed in claim 1, wherein the register contains the maximum value of the parameter supplied over a period and the average value of the parameter supplied over a period.

40. A monitor device as claimed in claim 39, wherein the maximum value of the parameter supplied over a period is updated at a first rate, and the average value of the parameter supplied over a period is updated at a second rate slower than the first rate.

41. A monitoring device as claimed in claim 1, wherein the register contains the minimum value of the parameter supplied over a period and the average value of the parameter supplied over a period.

42. A monitoring device as claimed in claim 41, wherein the minimum value of the parameter supplied over a period is updated at a second rate slower than the first one.

43. A monitoring device as claimed in claim 1, wherein the register contains the maximum value of the parameter supplied over a period since the register was last accessed by the processor.

44. A monitoring device as claimed in claim 1, wherein the register contains the minimum value of the parameter supplied over a period since the register was last accessed by the processor.

45. A monitoring device as claimed in claim 1, wherein the register contains the average value of the parameter supplied over a fixed period.

50. A mobile communications device, comprising a monitoring device as claimed in claim 20.

51. A mobile communications device as claimed in claim 12, said monitor monitoring a parameter derived from a second analog signal corresponding to a charging current supplied by the battery, wherein:

said second analog signal is digitized by said analog-digital converter for producing information in said digital signal stream corresponding to successive measurements of the charging current;

said output register contains values of output parameters derived from said digital signal stream, said values corresponding to said voltage and current measurements; and

said logic unit is adapted for updating the value of each of the output parameters contained in the register as required in response to said digital signal stream.

24. A method of monitoring a value of a parameter derived from an analog signal, the method comprising:

producing a digital signal corresponding to the analog signal, wherein said digital signal comprises a digital signal stream, corresponding to successive measured values of the parameter;

obtaining at least one value of said parameter, based on the digital signal; and

storing at least one said obtained at least one value derived from said digital stream in an output register, accessible by a processor unit.

25. A method as claimed in claim 24, further comprising setting a threshold value for said parameter, and for sending a signal to said processor when the value of the parameter reaches the threshold value.

26. A method of monitoring as claimed in claim 24, wherein said parameter comprises a voltage supplied by a battery.

27. A method as claimed in claim 26, comprising updating the value of the or each parameter contained in the register as required in response to the digital stream.

28. A method as claimed in claim 27, wherein the register contains the maximum value of the battery voltage supplied over a period since the register was last accessed by the processor.

29. A method as claimed in claim 27, wherein the register contains the minimum value of the battery voltage supplied over a period since the register was last accessed by the processor.

30. A method of monitoring as claimed in claim 24, wherein said parameter comprises a charging current supplied to a battery.

31. A method as claimed in claim 27, wherein the register contains the average value of the battery voltage supplied over a fixed period.

32. A method as claimed in claim 30, comprising updating the value of the or each parameter contained in the register as required in response to the digital signal stream.

33. A method as claimed in claim 32, comprising storing in the register the maximum value of the charging current supplied over a period since the register was last accessed by the processor.

34. A method of monitoring as claimed in claim 24, wherein said parameter comprises a temperature.

35. A monitoring device as claimed in claim 32, comprising storing in the register the minimum value of the charging current supplied over a period since the register was last accessed by the processor.

36. A method as claimed in claim 32, comprising storing in the register the average value of the charging current supplied over a period.

37. A method as claimed in claim 34, comprising updating the value of the or each parameter contained in the register as required in response to the digital signal stream.

46. A method as claimed in claim 24, comprising updating the value of the or each parameter contained in the register as required in response to the digital signal stream.

47. A monitoring device as claimed in claim 37, comprising storing in the register the maximum value of the temperature supplied over a period since the register was last accessed by the processor.

48. A method as claimed in claim 37, comprising storing in the register the minimum value of the temperature supplied over a period since the register was last accessed by the processor.

49. A method as claimed in claim 37, comprising storing in the register the average value of the temperature supplied over a fixed period.