Systems and methods for charging a chargeable USB device

• US 8,154,245 B2
• Filed: 02/07/2011
• Issued: 04/10/2012
• Est. Priority Date: 02/15/2005
• Status: Active Grant

• Current Assignee: Fundamental Innovation Systems International LLC (Fundamental Innovation Systems International Holdings LLC)
• Original Assignee: Blackberry Limited
• Inventors: Veselic, Dusan
• Primary Examiner(s): Tso, Edward
• Assistant Examiner(s): TORRES RUIZ, JOHALI ALEJANDRA
• Application Number:
  US13/022,541
• Publication Number:
  US 20110127950A1
• Time in Patent Office: 428 Days
• Field of Search: 320/107
• US Class Current: 320/107
• 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 2207/30 Charge provided using DC bus or data bus of a computer
• CPC Class Codes: H02J 7/0034 using reverse polarity correcting or protecting circuits mechanical means of polarity protection H02J7/0045

Abstract

Systems and methods are provided for charging a USB device. A USB connector may be used to couple the system to a USB port on the USB device, the USB connector including a bus voltage (Vbus) connector, a positive data (D+) connector, and a negative data (D−) connector. Charger circuitry may be used to receive a source voltage and convert the source voltage into the bus voltage (Vbus), wherein the bus voltage (Vbus) is used to charge the USB device. Presence detect circuitry may be used to compare a first voltage present on the D+ connector with a second voltage present on the D− connector in order to detect when the USB connector is coupled to the USB port of the USB device.

Claims

1. A method for detecting whether a universal serial bus (USB) device is connected to a USB charger, the method comprising:

pulling a first data line and a second data line within a high logic voltage range, the first data line having a first voltage level that is higher than a second voltage level of the second data line when each data line is in the high logic voltage range;

monitoring the first voltage level and the second voltage level; and

detecting whether the USB device is connected to the USB charger based on a variation between the first voltage level and the second voltage level.

2. The method of claim 1, wherein connecting the USB device to the USB charger causes the first data line and the second data line to be pulled within a low logic voltage range, and

wherein the second voltage level is higher than the first voltage level when the first data line and the second data line are each in the low logic voltage range.

3. The method of claim 2, wherein the first data line is a negative data line and the second data line is a positive data line.

4. The method of claim 1, further comprising:

attempting to perform a USB enumeration upon detecting power on a voltage bus line operable to connect the USB device to the USB charger; and

determining the USB device is connected to the USB charger if the USB enumeration fails.

5. The method of claim 4, further comprising:

communicating a signal instructing the USB charger to begin charging the USB device upon determining the USB device is connected to the USB charger.

6. The method of claim 5, further comprising:

generating a regulated voltage and/or current for use by the USB charger in charging the USB device.

7. The method of claim 1, wherein the high logic voltage range includes a range of about 3.0 V to about 3.6 V.

8. A circuit operable to detect when a universal serial bus (USB) device connects to a USB charger via a USB connector, the USB connector including at least a first data line and a second data line, the circuit comprising:

detection circuitry operable to compare a first voltage of the first data line with a second voltage of the second data line while each data line is in a high logic state, the first voltage being higher than the second voltage when the first data line and the second data line are each in the high logic state,

the detection circuitry being configured to determine whether the USB device is connected to the USB charger based on a voltage change between the first voltage and the second voltage.

9. The circuit of claim 8, wherein the first data line and the second data line are in a low logic state when the USB device is connected to the USB charger.

10. The circuit of claim 9, wherein the detection circuitry includes a first voltage divider circuit and a second voltage divider circuit, each voltage divider having resistor values for generating a USB “

Illegal”

output and a “

USB”

reset output when the first data line and the second data line are in the high logic state and the low logic state, respectively.

11. The circuit of claim 8, wherein the first data line is a negative data line and the second data line is a positive data line.

12. The circuit of claim 8, wherein the first voltage and the second voltage include voltages ranging from about 3.0 V to about 3.6 V when the first data line and the second data line are in the high logic state.

13. The circuit of claim 8, further comprising:

circuitry for generating a first regulated voltage and/or current for use in detecting whether the USB device is connected to the USB charger and a second regulated voltage and/or current for use in charging the USB device when connected to the USB charger.

14. A system for detecting whether a universal serial bus (USB) device is connected to a USB charger, the system comprising:

a USB connector for connecting the USB device to the USB charger, the USB connector including a first data line, a second data line, and a power line, the first data line and the second data line having a first voltage and a second voltage within a voltage range for a high logic state; and

a detection circuit operable to detect when the USB device is connected to the USB charger via the USB connector, the detection circuit being configured to compare the first voltage with the second voltage, and determine whether the USB device is connected to the USB charger based on a variance between the first voltage and the second voltage.

15. The system of claim 14, wherein the variance causes the second voltage to become higher than the first voltage such that the first data line and the second line are in a low logic state.

16. The system of claim 15, wherein the detection circuit includes a first voltage divider circuit and a second voltage divider circuit, each voltage divider having resistor values for generating a USB “

Illegal”

output and a “

USB”

reset output when the first data line and the second data line are in the high logic state and the low logic state, respectively.

17. The system of claim 14, wherein the first voltage and the second voltage include voltages ranging from about 3.0 V to about 3.6 V when the first data line and the second data line are in the high logic state.

18. The system of claim 14, wherein the first data line is a negative data line and the second data line is a positive data line.

19. The system of claim 14, wherein the USB device includes a processing device operable to attempt a USB enumeration upon detecting power on the power line, and

wherein the detection circuit determines the USB device is connected to the USB charger if the USB enumeration is not successful.

20. The system of claim 14, further comprising:

circuitry for generating a first regulated voltage and/or current for use in detecting whether the USB device is connected to the USB charger and a second regulated voltage and/or current for use in charging the USB device when connected to the USB charger.