Apparatus and method for producing signal conveying circuit status information

Abstract

Apparatus is configured for producing an output signal indicating an operating status of a monitored circuit. An input signal relating to the monitored circuit is received at an input node. A pulse train generator, coupled to the input node, is configured for generating a pulse train of a prescribed repetition rate at a duty cycle alternated between first and second duty cycle values at a prescribed frequency. The duty cycle and frequency are indicative of operating status of the monitored circuit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of the subject matter claimed herein are illustrated in the figures of the accompanying drawings and in which reference numerals refer to similar elements and in which:

FIG. 1 shows examples of status signals that may be produced by an LED, or the like, to provide information.

FIG. 2 is an exemplary diagram illustrating a battery charger according to one embodiment of the disclosure.

FIG. 3 is an example of waveforms of low and high frequency pulse trains and a serrated pulse train according to one embodiment of the disclosure.

FIG. 4 is an exemplary diagram showing spectra corresponding to the low and high frequency pulse trains and the serrated pulse train in FIG. 3.

FIG. 5 is an example of a circuit topology for adjusting LED current for various blink rates of the serrated pulse train according to one embodiment of the disclosure.

FIG. 6 is a first exemplary block diagram of a pulse generator according to an embodiment of the disclosure.

FIG. 7 is a second exemplary block diagram of a pulse generator according to an embodiment of the disclosure.

FIG. 8 is a third exemplary block diagram of a pulse generator according to an embodiment of the disclosure.

FIG. 9 is a fourth exemplary block diagram of a pulse generator according to an embodiment of the disclosure.

FIG. 10 is an example of a circuit topology of an oscillator according to an embodiment of the disclosure.

FIG. 11 is exemplary waveforms of the oscillator shown in FIG. 10.

FIG. 12 is an example of a circuit topology of a frequency divider according to an embodiment of the disclosure.

FIG. 13 is an example of a flip-flop circuit implemented in the frequency divider of FIG. 12.

FIG. 14 is an example of a circuit topology of a serrated pulse generator and a deglitcher used for a battery charger according to an embodiment of the disclosure.

FIGS. 15A-1SE shows exemplary waveforms generated by the oscillator of FIG. 10, the frequency divider of FIG. 12 and the serrated pulse generator of FIG. 14.

FIG. 16 is an example of waveforms illustrating synchronization of edges of pulses according to an embodiment of the disclosure.

FIGS. 17A and 17B are exemplary timing charts showing generation of a serrated pulse train according to an embodiment of the disclosure.

FIG. 18 is an exemplary timing chart showing generation of truncated clock signals according to an embodiment of the disclosure.

FIG. 19 is an exemplary block diagram illustrating connection of a /CHRG pin of a battery charger according to an embodiment of the disclosure.

FIG. 20 is an example of a modified serrated signal according to an embodiment of the disclosure.

FIG. 21 is an example of a circuit topology of another serrated pulse generator configured for providing multiple status bits used for a battery charger according to an embodiment of the disclosure.

FIGS. 22-25 are exemplary simulated waveforms generated in the circuit shown in FIG. 21, in which FIG. 22 shows a simulation with data bit B0=L and data bit B1=L, FIG. 23 shows a simulation with data bit B0=H and data bit B1=L, FIG. 24 shows a simulation with data bit B0=L and data bit B1=H, and FIG. 25 shows a simulation with data bit B0=H and data bit B1=H.

FIG. 26 is an exemplary diagram illustrating a modified battery charger according to one embodiment of the disclosure.

FIG. 27 is an exemplary circuit topology of control logic for a multiple-bit receiver included in the battery charger of FIG. 26.

FIG. 28 is exemplary simulated waveforms explaining operation of the control logic shown in FIG. 27.

Claims

1. Apparatus for producing an output signal indicating an operating status of a monitored circuit, comprising: an input node for receiving an input signal relating to the monitored circuit;a pulse train generator coupled to the input node and configured for generating a pulse train of a prescribed repetition rate at a duty cycle alternated between first and second duty cycle values at a prescribed frequency,in which the duty cycle and frequency are indicative of operating status of the monitored circuit; andan output node to which the pulse train is applied.

2. The apparatus according to claim 1, wherein duty cycle information is adapted to be supplied to a processor, and frequency information is adapted to be supplied to a user discernible output device.

3. The apparatus according to claim 2, wherein the user discernible output device is a light emitting device.

4. The apparatus according to claim 1, wherein the output node is adapted to be coupled to a processor and a light emitting device, in which the duty cycle conveys status information to the processor, and the frequency conveys status information to a user.

5. The apparatus according to claim 4, wherein the first duty cycle value is relatively low such that the light emitting device presents a visual cue of relatively low intensity, and the second duty cycle value is relatively high such that the light emitting device presents a visual cue of relatively high intensity.

6. The apparatus according to claim 5, wherein the first duty cycle value is about 10% or less, andthe second duty cycle value is about 90% or more.

7. The apparatus according to claim 5, further wherein the prescribed frequency alternates at a value such that the light emitting device presents a visual cue that alternates visibly between the relatively high and relatively low intensities.

8. The apparatus according to claim 7, wherein the prescribed frequency is about 10 Hz or less.

9. The apparatus according to claim 1, wherein the prescribed repetition rate of the pulse train is out of an audio frequency band.

10. The apparatus according to claim 9, wherein the prescribed repetition rate is greater than approximately 20 KHz.

11. The apparatus according to claim 1, wherein the pulse train generator is configured for varying the first and second duty cycle values and the prescribed frequency based on the operating status of the monitored circuit.

12. The apparatus according to claim 1, wherein the pulse train generator is further configured for generating a bit packet indicating the operating status of the monitored circuit, and embedding the bit packet in the pulse train.

13. The apparatus according to claim 12, wherein the bit packet includes one or more bits.

14. The apparatus according to claim 13, wherein a repetition rate of the bits is out of an audio frequency band.

15. The apparatus according to claim 14, wherein the repetition rate of the bits is greater than approximately 20 KHz.

16. The apparatus according to claim 12, wherein the pulse train generator embeds the bit packet in an interval of pulses in the pulse train.

17. The apparatus according to claim 1, wherein the pulse train generator includes a circuit configured for removing spurious glitches from the pulse train.

18. The apparatus according to claim 1, further comprising: a decoder for receiving and decoding a pulse train of a prescribed repetition rate at a duty cycle alternated between third and fourth duty cycle values at a prescribed frequency to obtain an instruction, anda controller for controlling the apparatus based on the instruction.

19. The apparatus according to claim 18, wherein the pulse train further includes a bit packet for conveying the instruction.

20. A battery charger for charging a battery, comprising: a detector detecting an operating status of a battery; anda pulse train generator coupled to the detector and configured for generating a pulse train of a prescribed repetition rate at a duty cycle alternated between first and second duty cycle values at a prescribed frequency,in which the duty cycle and frequency are indicative of operating status of the battery; andan output node to which the pulse train is applied.

21. The battery charger according to claim 20, wherein the output node is adapted to be coupled to a processor and a light emitting device, in which the duty cycle conveys status information to the processor, and the frequency conveys status information to a user.

22. The battery charger according to claim 21, wherein the first duty cycle value is relatively low such that the light emitting device presents a visual cue of relatively low intensity, and the second duty cycle value is relatively high such that the light emitting device presents a visual cue of relatively high intensity.

23. The battery charger according to claim 22, wherein the first duty cycle value is about 10% or less, andthe second duty cycle value is about 90% or more.

24. The battery charger according to claim 22, further wherein the prescribed frequency alternates at a value such that the light emitting device presents a visual cue that alternates visibly between the relatively high and relatively low intensities.

25. The battery charger according to claim 24, wherein the prescribed frequency is about 10 Hz or less.

26. The battery charger according to claim 20, wherein the prescribed repetition rate of the pulse train is out of an audio frequency band.

27. The battery charger according to claim 26, wherein the prescribed repetition rate is greater than approximately 20 KHz.

28. The battery charger according to claim 20, wherein the pulse train generator is configured for varying the first and second duty cycle values and the prescribed frequency based on the operating status of the monitored circuit.

29. The battery charger according to claim 20, wherein the detector is configured to detect whether the battery is being charged or not, and whether the battery is in a prescribed condition, andthe pulse train generator generates the pulse train in response to the prescribed condition.

30. The battery charger according to claim 29, wherein the prescribed condition includes whether the battery is defective and whether the battery is in an out of temperature range, andthe pulse train generator varies the first and second duty cycle values and the prescribed frequency based on the condition detected.

31. The battery charger according to claim 20, wherein the pulse train generator is further configured for generating a bit packet indicating the operating status of the monitored circuit, and embedding the bit packet in the pulse train.

32. The battery charger according to claim 31, wherein the bit packet includes one or more bits.

33. The battery charger according to claim 32, wherein a repetition rate of the bits is out of an audio frequency band.

34. The battery charger according to claim 33, wherein the repetition rate of the bits is greater than approximately 20 KHz.

35. The battery charger according to claim 31, wherein the pulse train generator embeds the bit packet in an interval of pulses in the pulse train.

36. The battery charger according to claim 20, wherein the pulse train generator includes a circuit configured for removing spurious glitches from the pulse train.

37. The battery charger according to claim 20, further comprising: a decoder for receiving and decoding a pulse train of a prescribed repetition rate at a duty cycle alternated between third and fourth duty cycle values at a prescribed frequency to obtain an instruction, anda controller for controlling the apparatus based on the instruction.

38. The battery charger according to claim 37, wherein the pulse train includes a bit packet for conveying the instruction.

39. A method for producing status information relating to a monitored circuit, comprising the steps of: receiving an input signal relating to the monitored circuit; andgenerating a pulse train of a prescribed repetition rate at a duty cycle alternated between first and second duty cycle values at a prescribed frequency based on the input signal,in which the duty cycle and frequency are indicative of operating status of the monitored circuit.

40. The method according to claim 39, further comprising the step of outputting the pulse train to a processor and a user discernible output device, in which the duty cycle conveys the status information to the processor, and the frequency conveys the status information to a user through the user discernible output device.

41. The apparatus according to claim 39, wherein the pulse train generating step includes generating a bit packet indicating the operating status of the monitored circuit, and embedding the bit packet in the pulse train.