USB Dedicated Charger Identification Circuit

• US 20110276734A1
• Filed: 11/03/2009
• Published: 11/10/2011
• Est. Priority Date: 11/03/2009
• Status: Active Grant

• Current Assignee: Maxim Integrated Products, Inc. (Analog Devices, Inc.)
• Original Assignee: Maxim Integrated Products, Inc. (Analog Devices, Inc.)
• Inventors: Helfrich, Kenneth
• Granted Patent: US 8,358,100 B2
• Time in Patent Office: Days
• US Class Current: 710/105
• 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: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/00038 using passive battery identification means, e.g. resistors or capacitors identification by mechanical connections H02J7/0045
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction

Abstract

In an embodiment, set forth by way of example and not limitation, a USB dedicated charger identification circuit includes a USB D+ port, a USB D− port, a first circuit conforming to a first identification protocol, a second circuit conforming to a second identification protocol, and logic selectively coupling one of the first circuit and the second circuit to the USB D+ port and the USB D− port. In an alternate embodiment set forth by way of example and not limitation, a method to provide USB charger identification includes providing a first USB charger identification at a USB D+ port and a D− port. Next, it is detected if the first USB charger identification was inappropriate. Then, if the first USB charger identification was inappropriate, a second USB charger identification is provided at the USB D+ port and the D− port.

Claims

1. A USB dedicated charger identification circuit comprising:

a USB D+ port;

a USB D−

port;

a first circuit conforming to a first identification protocol;

a second circuit conforming to a second identification protocol; and

logic selectively coupling one of said first circuit and said second circuit to said USB D+ port and said USB D−

port.

2. A USB dedicated charger identification circuit as recited in claim 1 wherein said first circuit comprises a voltage divider.

3. A USB dedicated charger identification circuit as recited in claim 2 wherein said voltage divider is a first voltage divider, and wherein said first circuit further comprises a second voltage divider coupled in parallel with said first voltage divider.

4. A USB dedicated charger identification circuit as recited in claim 3 wherein said second circuit is a conductor.

5. A USB dedicated charger identification circuit as recited in claim 4 wherein said logic couples said first circuit to said USB D+ port and said USB D−

port as a default condition.

6. A USB dedicated charger identification circuit as recited in claim 5 wherein said logic includes an electronic switch having at least two poles with at least two throws per pole.

7. A USB dedicated charger identification circuit as recited in claim 6 wherein said electronic switch couples said first circuit and said second circuit to said USB D+ port and said USB D−

port.

8. A USB dedicated charger identification circuit as recited in claim 7 wherein said logic further comprises circuitry having an input coupled to at least one of said USB D+ port and said USB D−

port and an output coupled to said electronic switch.

9. A USB dedicated charger identification circuit as recited in claim 8 wherein said output of said circuitry is connected to a control input of said electronic switch.

10. A USB dedicated charger identification circuit as recited in claim 8 wherein said output of said control circuitry is coupled to a control input of said electronic switch by control logic which controls an operational mode.

11. A USB dedicated charger identification circuit as recited in claim 8 wherein said logic comprises a bistable multivibrator.

12. A method to provide USB charger identification comprising:

providing a first USB charger identification at a USB D+ port and a USB D−

port;

detecting if said first USB charger identification was inappropriate; and

providing a second USB charger identification at said USB D+ port and said USB D−

port if said first USB charger identification was inappropriate.

13. A method to provide USB charger identification as recited in claim 12 wherein said first USB charger identification is a default identification.

14. A method to provide USB charger identification as recited in claim 12 wherein said default identification is for an undetectable protocol at said USB D+ port and said USB D−

port.

15. A method to provide USB charger identification as recited in claim 14 wherein said undetectable protocol is a charger identification protocol developed by Apple Computer, Inc.

16. A method to provide USB charger identification as recited in claim 15 wherein said wherein said second USB charger identification is a detectable protocol at said USB D+ port and said USB D−

port.

17. A method to provide USB charger identification as recited in claim 16 wherein said detectable protocol is a USBIF charger identification protocol.

18. A USB charger identification apparatus comprising:

means for providing a first USB charger identification at a USB D+ port and a USB D−

port;

means for detecting if said first USB charger identification was inappropriate; and

means for providing a second USB charger identification at said USB D+ port and said USB D−

port if said first USB charger identification was inappropriate.

19. A USB charger identification apparatus as recited in claim 18 wherein said means for detecting comprises circuitry having an input coupled to at least one of said USB D+ port and said USB D−

port and a control output.

20. A USB charger identification apparatus as recited in claim 19 wherein said means for providing comprises an electronic switch coupled to said control output of said circuitry.