Systems and methods for providing device-to-device handshaking through a power supply signal

• US 20080309313A1
• Filed: 06/13/2008
• Published: 12/18/2008
• Est. Priority Date: 06/15/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Sander, Brian, Heyl, Lawrence, Farrar, Doug
• Granted Patent: US 8,332,664 B2
• Time in Patent Office: Days
• US Class Current: 323/351
• CPC Class Codes: G06F 1/266 Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips
• CPC Class Codes: G06F 13/4081 Live connection to bus, e.g. hot-plugging current or voltage limitation during live insertion H02H9/004
• CPC Class Codes: G06F 21/81 by operating on the power supply, e.g. enabling or disabling power-on, sleep or resume operations
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

Handshaking circuits are provided in a communications cable and in a device operable to be mated with the communications cable. Before a device can utilize the power supply signal of such a communications channel, the two handshaking circuits must sufficiently identify one another over a power supply signal with a decreased voltage. The decreased voltage allows for a cable plug to be provided with a safe, protected power that cannot cause harm to a human. The decreased voltage also reduces the chance that a device can receive a primary power supply signal from the cable before the device sufficiently identifies itself. Accordingly, a laptop may be connected to a portable music player, but the voltage of the power supply signal provided by the laptop to the cable may be decreased on-cable until the handshaking circuit of the portable music player sufficiently performs a handshaking operation with a on-cable handshaking circuit.

Claims

1. A system comprising:

a cable including a first plug and a second plug;

a first circuit located on said cable;

a device, wherein a second circuit is located on said device that receives a power supply signal in a form regulated by said first circuit and instructs said first circuit to provide said power supply signal in unregulated form.

2. A method comprising:

receiving a power supply signal;

stepping-down said power supply signal;

recognizing said stepped-down power signal for a pre-determined amount of time;

introducing current spikes into said power supply signal after said stepped-down power signal has been recognized for said pre-determined amount of time;

recognizing said current spikes; and

stepping-up said voltage in response to said recognized current spikes.

3. A method comprising:

receiving a power supply signal on a first plug of a cable;

stepping-down, on said cable, the voltage of said power supply signal;

providing said stepped-down power supply signal to a second plug of said cable, wherein said second plug is mated with a device;

receiving information from said device through said stepped-down power signal provided to said device.

4. The method of claim 3, wherein said information provides instructions to perform an operation on said cable to said stepped-down power supply signal.

5. The method of claim 4, wherein said operation comprises stepping-up said stepped-down power supply signal.

6. A method comprising:

determining whether the voltage of a received power supply signal is within a particular range;

if the voltage of said power supply signal is within said particular range, manipulating the current of said power supply signal;

recognizing said manipulated current;

increasing the voltage of said received power supply signal above said particular range in response to said recognized manipulated current.

7. The method of claim 6, wherein said power supply signal is received from an on-cable circuit, said recognizing is performed on a device, and said increasing is performed by said on-cable circuit.

8. A method comprising:

receiving on a device a first handshake signal from an on-cable circuit, wherein said first handshake signal is provided in a power supply signal for said device;

providing a second handshake signal from said device to said on-cable circuit in response to the first handshake signal, wherein said second handshake signal is provided in said power supply signal; and

changing at least one characteristic of said power supply signal in response to said second handshake signal.

9. A system comprising:

a first circuit comprising;

an input node for receiving a power signal;

a voltage detector for determining whether said power signal meets a voltage threshold;

a timing circuit, wherein said timing circuit is enabled based on whether said voltage threshold is met and said timing circuit performs a counting operation so long as said voltage threshold is met; and

a pulse generator circuit, wherein said pulse generator circuit provides current pulses to said power signal after said counting operation is performed for a pre-determined amount of time.

10. The system of claim 9, further comprising a second circuit for providing said power signal and detecting said current pulses in said power signal.

11. The system of claim 10, further comprising a second circuit for providing said power signal, said first circuit is provided on a device, and said second circuit is provided on a cable operable to electrically couple with said device.

12. An on-cable handshaking circuit comprising:

an input node for receiving a power supply signal;

a first circuit, wherein said first circuit decreases the voltage of said power supply signal received at said input node and provides said decreased power supply signal to an output node; and

a current detector, wherein said current detector provides a control signal based on the current of said power supply signal on said output node and the voltage of said power supply signal on said output node is increased in response to said control signal.

13. The on-cable handshaking circuit of claim 12, wherein a device is coupled to said output node and introduces current pulses into said output node in order to cause said current detector to generate said control signal.

14. An on-device handshaking circuit comprising:

an input node for receiving a power signal;

a voltage detector for determining whether said power signal meets a voltage threshold;

a timing circuit, wherein said timing circuit is enabled based on whether said voltage threshold is met, said timing circuit performs a counting operation based on whether said voltage threshold is met, and said timing circuit provides a control signal; and

a pulse generator circuit, wherein said pulse generator circuit provides a current pulse to said power signal based on said control signal.

15. A method for using a power supply signal between a first device and a second device, the method comprising:

receiving the power supply signal with a first handshaking circuitry of the first device;

changing a first characteristic of the power supply signal, wherein the first characteristic is changed by the first handshaking circuitry;

recognizing the changed first characteristic with a second handshaking circuitry of the second device;

introducing current spikes into the power supply signal in response to recognizing the changed first characteristic, wherein the current spikes are introduced by the second handshaking circuitry;

recognizing the current spikes with the first handshaking circuitry; and

altering a second characteristic of the power supply signal in response to recognizing the current spikes, wherein the second characteristic is altered by the first handshaking circuitry.

16. The method of claim 15, wherein changing the first characteristic of the power supply signal comprises stepping-down the voltage level of the power supply signal.

17. The method of claim 15, wherein altering the second characteristic of the power supply signal comprises stepping-up the voltage of the power supply signal.

18. The method of claim 15, wherein recognizing the changed first characteristic comprises determining that the voltage level of the power supply signal is within a particular range for a pre-determined amount of time.

19. The method of claim 15, wherein the first device is a cable that is coupled to the second device, and wherein the first handshaking circuitry is located within the cable.

20. The method of claim 19, wherein the cable comprises one or more plugs.

21. The method of claim 20, wherein at least one of the plugs is a Universal Serial Bus plug.

22. The method of claim 20, wherein at least one of the plugs is a 30-pin connector plug.

23. The method of claim 15, wherein the first device is a power supply, and wherein the first handshaking circuitry is located within the power supply.

24. The method of claim 15, wherein the first device is an accessory device for the second device, and wherein the first handshaking circuitry is located within the accessory device.

25. A method for receiving authentication with an accessory device of a main device, the method comprising:

transmitting a power supply signal from the accessory device to the main device;

receiving a query from the main device that requests a handshake signal from the accessory device in order to authenticate the accessory device;

transmitting a handshake signal in the power supply signal from the accessory device to the main device; and

authenticating the handshake signal with the main device.

26. The method of claim 25, further comprising allowing the power from the power supply signal to be used in the main device in response to authenticating the handshake.

27. A method for using a power supply signal between a device and a cable, the method comprising:

receiving, on the device, a first handshake signal from handshaking circuitry of the cable, wherein the first handshake signal is provided in a power supply signal for the device;

providing a second handshake signal from the device to the handshaking circuitry in response to the first handshake signal, wherein the second handshake signal is provided in the power supply signal; and

changing at least one characteristic of the power supply signal with the handshaking circuitry in response to the second handshake signal.

28. A system comprising:

first handshaking circuitry, wherein the first handshaking circuitry is located in a first device and is configured to;

receive a power supply signal; and

change a first characteristic of the power supply signal;

second handshaking circuitry located in a second device, wherein the second handshaking circuitry is configured to recognize the changed first characteristic of the power supply signal;

pulse generator circuitry, wherein the pulse generator circuitry is located in the second device and is configured to provide current spikes to the power supply signal in response to the second handshaking circuitry recognizing the changed first characteristic; and

a current detector, wherein the current detector is located in the first device and is configured to recognize the current spikes, and wherein the first handshaking circuitry is further configured to alter a second characteristic of the power supply signal in response to the current detector recognizing the current spikes.

29. The system of claim 28, wherein the first handshaking circuitry changing the first characteristic of the power supply signal comprises stepping-down the voltage level of the power supply signal.

30. The system of claim 28, wherein the first handshaking circuitry altering the second characteristic of the power supply signal comprises stepping-up the voltage of the power supply signal.

31. The system of claim 28, wherein the second handshaking circuitry recognizing the changed first characteristic further comprises determining that the voltage level of the power supply signal is within a particular range for a pre-determined amount of time.

32. The system of claim 28, wherein the first device is a cable that is coupled to the second device, and wherein the first handshaking circuitry is located within the cable.

33. The system of claim 32, wherein the cable comprises one or more plugs.

34. The system of claim 33, wherein at least one of the plugs is a Universal Serial Bus plug.

35. The system of claim 33, wherein at least one of the plugs is a 30-pin connector plug.

36. The system of claim 28, wherein the first device is a power supply, and wherein the first handshaking circuitry is located within the power supply.

37. The system of claim 28, wherein the first device is an accessory device for the second device, and wherein the first handshaking circuitry is located within the accessory device.

38. A system comprising:

an accessory device, wherein the accessory device comprises a first processor configured to;

transmit a power supply signal from the accessory device to a main device;

receive a query from the main device requesting a handshake signal in order to authenticate the accessory device; and

transmit a handshake signal in the power supply signal to the main device; and

the main device, wherein the main device comprises a second processor configured to;

receive the handshake signal in the power supply signal from the accessory device; and

authenticate the handshake signal.

39. The system of claim 38, wherein the second processor is further configured to allow the power from the power supply signal to be used in the main device in response to authenticating the handshake signal.

40. An electronic device comprising:

electrical contacts for interfacing with another device;

handshaking circuitry electrically coupled to at least one of the electrical contacts, the handshaking circuitry operative to;

provide a power supply signal having a first characteristic to at least one of the electrical contacts;

monitor the power supply signal for current spikes; and

in response to monitoring current spikes, provide the power supply signal having a second characteristic.

41. A cable system comprising:

a multi-region jack including at least one electrical contact;

a universal serial bus (USB) plug electrically coupled to the multi-region jack with a cable, the USB plug comprising handshaking circuitry operative to;

provide a power supply signal having a first characteristic to the at least one of the electrical contacts;

monitor the power supply signal for current spikes; and

in response to monitoring current spikes, provide the power supply signal having a second characteristic.

42. The cable system of claim 41, wherein the multi-region jack is a four region jack having a diameter of about 3.5 mm.

43. The cable system of claim 41, wherein the USB plug is a male USB plug.

44. A system comprising:

a housing designed to accommodate at least 30 contacts spaced apart in a single row of sequentially numbered contact locations, wherein the sequentially numbered contact locations include digital contact locations, analog contact locations and ground contact locations;

at least one electrical contact disposed in a corresponding one of the contact locations;

handshaking circuitry electrically coupled to the at least one electrical contact, the handshaking circuitry operative to;

provide a power supply signal having a first characteristic to the at least one of the electrical contacts;

monitor the power supply signal for current spikes; and

in response to monitoring current spikes, provide the power supply signal having a second characteristic; and

at least one power contact for receiving power from a source external to the system.

45. The system of claim 44 further comprising:

a universal serial bus plug including the at least one power contact.

46. The system of claim 45, wherein the handshaking circuitry is included in the universal serial bus plug.

47. The system of claim 44 further comprising a circuit board including the handshaking circuitry and electrically coupled to the at least one electrical contact and the at least one power contact.

48. The system of claim 47, wherein the housing is mounted to the circuit board.

49. The system of claim 44, wherein the housing is a male plug connector for connecting to a corresponding receptacle of an electronic device.

50. The system of claim 44 further comprising:

a docking station including the housing, the at least one electrical contact, the handshaking circuitry, and the at least one power contact.

51. A system comprising

an interface for receiving a corresponding connector of another device, the interface including at least one electrical contact for receiving a power supply signal;

handshaking circuitry electrically coupled to the at least one electrical contact, the handshaking circuitry operative to;

recognize a power supply signal having a first characteristic of the power supply signal;

in response to recognizing the power supply signal having the first characteristic, introduce a validation signal to the power supply signal; and

receive the power supply signal having a second characteristic while the validation signal is introduced to the power supply signal.

52. The system of claim 51 further comprising:

non-volatile memory; and

a processor operative to communicate with the non-volatile memory and process one or more applications.

53. The system of claim 52 further comprising:

a user input interface for controlling one or more operations of the system.

54. The system of claim 51, wherein the interface is constructed to receive a multi-region jack.

55. The system of claim 51, wherein the interface is designed to accommodate at least 30 contacts spaced apart in a single row of sequentially numbered contact locations, wherein the sequentially numbered contact locations include digital contact locations, analog contact locations and ground contact locations.

56. The system of claim 51, wherein the interface is a docking connector having two sets of keying arrangement, a first-make, last break ground contact, and a plurality of contacts arranged in a single row, the plurality of contacts including digital and analog contacts.

57. The system of claim 51, wherein the validation signal comprises current spikes.