METHOD FOR SUPPLYING POWER TO AN PORTABLE ELECTRONIC DEVICE

• US 20150311738A1
• Filed: 04/20/2015
• Published: 10/29/2015
• Est. Priority Date: 04/23/2014
• Status: Active Grant

• Current Assignee: Lenovo PC International Limited (Lenovo Group Ltd.)
• Original Assignee: Lenovo Singapore Pte Limited (Lenovo Group Ltd.)
• Inventors: ODAOHHARA, SHIGEFUMI, NAGATA, NOZOMU
• Granted Patent: US 9,825,478 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• 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 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence

Abstract

A power system within a portable electronic device is disclosed. In order to discharge electricity stored in a rechargeable battery within the portable electronic device to a discharge cutoff voltage, a charge booster charges the rechargeable battery with electric power coming from an AC/DC adaptor. When the AC/DC adaptor is detached, the charge booster performs boosting operation to supply power to a load from the rechargeable battery. The charge booster operates only when input voltage of the load decreases. A direct discharge circuit operates in conjunction with the charge booster, and when the charge booster does not perform any boosting operation, electric power is supplied directly from the rechargeable battery to a DC/DC converter. The charge booster can keep the input voltage of the DC/DC converter until the voltage reaches a discharge cutoff voltage of the rechargeable battery, and then stops operation when electric power is being supplied from the direct discharge circuit.

Claims

1. A power system comprising:

a rechargeable battery for supplying power to a load within a portable electronic device;

a charge booster configured to boost an output voltage of said rechargeable battery for supplying power to said load; and

a direct discharge circuit, operates in conjunction with said charge booster, configured to supply power to said load from said rechargeable battery without passing through said charge booster.

2. The power system of claim 1, wherein said charge booster includes a switching regulator having a rectifier that performs switching operation, and a switching controller that controls said rectifier.

3. The power system of claim 2, wherein said switching regulator charges said rechargeable battery with power supplied by an AC/DC adaptor.

4. The power system of claim 2, wherein said direct discharge circuit includes a bypass switch that operates in conjunction with switching operation of said rectifier.

5. The power system of claim 4, wherein said bypass switch shifts to an ON state when input voltage of said load reaches a first threshold such that said switching controller can stop its operation.

6. The power system of claim 5, wherein said switching controller performs switching operation to boost output voltage of said rechargeable battery when input voltage of said load is less than a second threshold that is lower than said first threshold.

7. The power system of claim 6, wherein said switching controller controls said bypass switch to be in an OFF state when said rectifier performs switching operation, and said switching controller controls said bypass switch to be in an ON state when said rectifier stops switching operation.

8. A portable electronic device comprising:

a load;

a rechargeable battery for supplying power to said load;

a charge booster for boosting an output voltage of said rechargeable battery to supply power to said load via a boosting/discharge route, wherein said charge booster boosts output voltage of said rechargeable battery to supply power to said load when input voltage of said load is less than a first threshold; and

a direct discharge circuit for supplying power to said load from said rechargeable battery via a direct discharge route, wherein said direct discharge circuit supplies power to said load while bypassing said boosting/discharge route when said input voltage is reaches said first threshold.

9. The portable electronic device of claim 8, wherein said portable electronic device further includes a charge route having a part of said boosting/discharge route, through which said rechargeable battery is charged with power from an AC/DC adaptor.

10. The portable electronic device of claim 9, wherein said portable electronic device further includes an external power-supply route through which power is supplied to said load from said AC/DC adaptor when power is supplied to said load through none of said boosting/discharge route and said direct discharge route.

11. A method comprising:

supplying power from a rechargeable battery to a load via a bypass circuit;

stopping power supply via said bypass circuit when input voltage of said load decreases less than a first threshold; and

boosting output voltage of said rechargeable battery by a charge booster and supplying power to said load when power supply via said bypass circuit has stopped.

13. The method of claim 12, wherein said method further includes stopping power supply from said charge booster and supplying power from said bypass circuit to said load when input voltage of said load is at a second threshold that is higher than said first threshold.

14. The method of claim 12, wherein said method further includes charging said rechargeable battery by said switching regulator when power is supplied from an AC/DC adaptor, wherein said charge booster includes a synchronous rectification type switching regulator.