METHOD AND APPARATUS FOR CHARGING A BATTERY IN A MOBILE DEVICE THROUGH A NEAR FIELD COMMUNICATION (NFC) ANTENNA

• US 20130157565A1
• Filed: 12/06/2012
• Published: 06/20/2013
• Est. Priority Date: 12/14/2011
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Clement, Patrick, Moret, Antoine
• Granted Patent: US 9,385,786 B2
• Time in Patent Office: Days
• US Class Current: 455/41.1
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A near field communication (NFC) antenna in a mobile device is used to wirelessly charge a battery in the mobile device by placing the mobile device on, or in very close proximity to, a charging station that emits an electromagnetic field. An induced current from the NFC antenna is detected that is above a predetermined threshold for longer than a predetermined duration. The induced current is used to charge the battery in the mobile device.

Claims

1. A method of wirelessly charging a battery in a mobile device, the mobile device including a near field communication (NFC) antenna, the method comprising:

detecting a current induced in the mobile device from the NFC antenna;

determining whether the current induced in the mobile device is above a predetermined threshold for longer than a predetermined duration; and

in response to the current induced in the mobile current being determined to be above the predetermined threshold for longer than the predetermined duration, using the current induced in the mobile device that is above the predetermined threshold to charge the battery in the mobile device.

2. The method of claim 1, wherein the NFC antenna is embedded in the mobile device.

3. The method of claim 2, wherein the mobile device comprises a NFC module coupled to the NFC antenna, wherein the NFC module is configured is to perform the detecting of the current induced in the mobile device.

4. The method of claim 3, wherein the NFC module enables the mobile device to wirelessly communicate with another NFC enabled device via a NFC communications protocol.

5. The method of claim 1, wherein:

the mobile device further comprises a power management module; and

using the current induced in the mobile device that is above the predetermined threshold to charge the battery in the mobile device comprises directing the current induced above the predetermined threshold to the power management module.

6. The method of claim 5, wherein using the current induced in the mobile device that is above the predetermined threshold to charge the battery in the mobile device comprises conditioning the current that is above the predetermined threshold to charge the battery in the mobile device.

7. A mobile device comprising:

a rechargeable battery;

a near field communication (NFC) antenna;

a NFC module coupled to the NFC antenna, the NFC module configured to

detect a level of a current induced in the NFC antenna;

determine whether the current induced in the NFC antenna is above a first predetermined threshold level for longer than a predetermined time duration; and

in response to the current induced in the NFC antenna being determined to be above the first predetermined threshold level for longer than the predetermined time duration, charge the rechargeable battery in the mobile device using the current induced in the NFC antenna that is above the first predetermined threshold level.

8. The mobile device of claim 7, wherein the NFC module is configured to shunt current above a second predetermined threshold level, wherein the second predetermined threshold level is less than the first predetermined threshold level.

9. The mobile device of claim 7, wherein the NFC module is configured to shunt current above the first predetermined threshold level for a time that is less than or equal to the predetermined time duration.

10. The mobile device of claim 7, wherein the NFC module is configured to direct the current induced in the NFC antenna that is above the first predetermined threshold to a power management module to charge the rechargeable battery in the mobile device.

11. The mobile device of claim 7, wherein the NFC module is implemented as part of a System-on-Chip (SoC) in the mobile device.

12. The mobile device of claim 7, wherein the NFC module includes a regulator and a power management module.

13. The mobile device of claim 12, wherein the regulator is configured to:

detect the level of the current induced in the NFC antenna that is above the first predetermined threshold level for longer than the predetermined time duration; and

direct the current induced in the NFC antenna that is above the first predetermined threshold level to the power management module.

14. The mobile device of claim 13, wherein the power management module is configured to condition the current induced in the NFC antenna that is above the first predetermined threshold level to charge the rechargeable battery.

15. The mobile device of claim 7, wherein upon detection that the level of the current induced in the NFC antenna that is above the first predetermined threshold level persists for longer than the predetermined time duration, the NFC module is configured to control an indicator to indicate that the rechargeable battery is charging.

16. The mobile device of claim 7, wherein the NFC module is configured to detect when the rechargeable battery is substantially fully charged, and to control an indicator to indicate that charging of the rechargeable battery is complete.

17. A method of wirelessly charging a battery in a mobile device, the method comprising:

monitoring a level of a current induced in a near field communication (NFC) antenna coupled to a NFC module embedded in the mobile device;

determining whether the level of the current induced in the NFC antenna is above a specified threshold level and persists for longer than a specified time duration;

in response to the current induced in the NFC antenna being determined to be above the specified threshold for longer than the specified time duration, directing the current induced in the NFC antenna above the specified threshold to a power management module; and

conditioning, by the power management module, the current induced in the NFC antenna above the specified threshold to charge the battery.

18. The method of claim 17, wherein the NFC module enables the mobile device to wirelessly communicate with another NFC enabled device via a NFC communications protocol.

19. The method of claim 17, wherein the current induced in the NFC antenna that is above the specified threshold is generated in response to the mobile device being placed on a charging station that emits an electromagnetic field.

20. The method of claim 17, wherein the NFC module is implemented as part of a System-on-Chip (SoC) in the mobile device.