Method and apparatus for handling a charging state in a mobile electronic device

• US 20050189909A1
• Filed: 12/30/2004
• Published: 09/01/2005
• Est. Priority Date: 02/17/2004
• Status: Active Grant

• Current Assignee: Fundamental Innovation Systems International LLC (Fundamental Innovation Systems International Holdings LLC)
• Original Assignee: Research In Motion Limited (Blackberry Limited)
• Inventors: Veselic, Dusan, Skarine, Alexei, Guthrie, Martin G. A., Habicher, Michael F.
• Granted Patent: US 7,679,316 B2
• Time in Patent Office: Days
• US Class Current: 320/107
• CPC Class Codes: G06F 1/263 Arrangements for using multiple switchable power supplies, e.g. battery and AC G06F1/30 takes precedence
• 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 13/385 for adaptation of a particular data processing system to different peripheral devices
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02J 7/342 The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging with circuits for polarity protection H02J7/0034

Abstract

In accordance with the teachings described herein, a method and apparatus for handling a charging state in a mobile device is provided. A universal serial bus (USB) interface may be used for connecting the mobile device to a USB host. A processing device may be used to execute programs and to control operation of the mobile device, the processing device may be further operable to receive an enumeration acknowledgement signal from the USB host via the USB interface. A rechargeable battery may be used for powering the processing device. A voltage regulator may be coupled to the USB interface and operable to receive a USB bus voltage from the USB interface and use the USB bus voltage to power the processing device. A timing circuitry may be used to disable the voltage regulator from powering the processing device after a pre-determined amount of time has expired, the timing circuitry being operable to measure the passage of the pre-determined amount of time upon detecting the USB bus voltage. A battery charger may be used to receive the USB bus voltage from the USB interface and use the USB bus voltage to power the processing device and to charge the rechargeable battery. The processing device may enable the battery charger to power the processing device and to charge the rechargeable battery when the enumeration acknowledgement signal is received from the USB host.

Claims

1. A mobile device, comprising:

a universal serial bus (USB) interface for connecting the mobile device to a USB host;

a processing device operable to execute programs and to control operation of the mobile device, the processing device being further operable to receive an enumeration acknowledgement signal from the USB host via the USB interface;

a rechargeable battery for powering the processing device;

a voltage regulator coupled to the USB interface and operable to receive a USB bus voltage from the USB interface and use the USB bus voltage to power the processing device;

a timing circuitry operable to disable the voltage regulator from powering the processing device after a pre-determined amount of time has expired, the timing circuitry being operable to measure the passage of the pre-determined amount of time upon detecting the USB bus voltage; and

a battery charger operable to receive the USB bus voltage from the USB interface and use the USB bus voltage to power the processing device and to charge the rechargeable battery;

wherein the processing device enables the battery charger to power the processing device and to charge the rechargeable battery when the enumeration acknowledgement signal is received from the USB host.

2. The mobile device of claim 1, wherein the processing device is further operable to disable both the voltage regulator and the battery charger if a device suspend state request signal is received from the USB host.

3. The mobile device of claim 1, further comprising:

a logic circuitry for selecting one of a voltage output of the voltage regulator or a voltage output of the battery charger to power the processing device.

4. The mobile device of claim 3, wherein the logic circuitry is a Diode OR circuitry.

5. The mobile device of claim 1, wherein the timing circuitry comprises:

a resistor-capacitor (RC) circuitry coupled to the USB interface for measuring the passage of the pre-determined amount of time; and

a switching circuitry that is controlled by the RC circuitry and is operable to disable the voltage regulator from powering the processing device.

6. The mobile device of claim 5, wherein the switching circuitry includes a transistor pair, wherein the RC circuitry causes the transistor pair to disconnect the voltage regulator from the processing device after the pre-determined amount of time has expired.

7. The mobile device of claim 1, wherein the pre-determined amount of time is an amount of time specified by the USB specifications during which the mobile device may be powered from the USB host without receiving the enumeration acknowledgement signal.

8. The mobile device of claim 7, wherein the pre-determined amount of time is less than or equal to 100 msec.

9. The mobile device of claim 1, wherein the voltage regulator is a low dropout (LDO) regulator.

10. The mobile device of claim 1, wherein the voltage regulator is a switched mode power supply (SMPS).

11. A method for powering a mobile device and charging a battery in the mobile device from a USB host, comprising:

detecting a USB bus voltage from the USB host;

upon detecting the USB bus voltage, measuring the passage of a pre-determined amount of time, the pre-determined amount of time being an amount of time specified by the USB specifications during which the mobile device may be powered from the USB host without receiving an enumeration acknowledgement signal;

after detecting the USB bus voltage and before the passage of the pre-determined amount of time, using a first circuitry to power the mobile device using the USB bus voltage;

monitoring the USB host for the enumeration acknowledgement signal;

if the enumeration acknowledgement signal is received before the pre-determined amount of time has expired, then using a second circuitry to power the mobile device and charge the battery using the USB bus voltage; and

once the pre-determined amount of time has expired, disabling the first circuitry from powering the mobile device using the USB bus voltage.

12. The method of claim 11, further comprising:

selecting one of the first circuitry or the second circuitry to power the mobile device.

13. The method of claim 11, further comprising:

monitoring the USB host for a device suspend state request signal;

if the device suspend state request signal is detected, then disabling the first circuitry and the second circuitry from powering the mobile device or charging the battery.

14. A mobile device, comprising:

a universal serial bus (USB) interface for connecting the mobile device to a USB host;

a rechargeable battery for powering the mobile device;

first means for powering the mobile device using a USB bus voltage from the USB host;

means for disabling the first powering means from powering the processing device after a pre-determined amount of time has expired from when the USB bus voltage is first detected; and

second means for powering the mobile device using the USB bus voltage;

wherein the second powering means is enabled to power the mobile device if an enumeration acknowledgement signal is received from the USB host before the pre-determined amount of time has expired.

15. The mobile device of claim 14, wherein the second power means also uses the USB bus voltage to charge a rechargeable battery.

16. The mobile device of claim 14, further comprising:

means for selecting one of the first power means or the second powering means to power the mobile device.

17. The mobile device of claim 14, further comprising:

means for detecting a device suspend state request signal from the USB host, and upon detecting the device suspend state request signal, disabling the first powering means and the second powering means from powering the mobile device using the USB bus voltage.