×

Charging circuit employing a southbridge microchip to control charging when the electronic apparatus is shut down

  • US 8,970,175 B2
  • Filed: 08/24/2011
  • Issued: 03/03/2015
  • Est. Priority Date: 06/03/2011
  • Status: Active Grant
First Claim
Patent Images

1. A charging circuit employed in an electronic apparatus for charging a battery of a portable electronic device, comprising:

  • a charging control microchip including two control terminals;

    a logic control circuit electronically connected to the two control terminals;

    a southbridge microchip electronically connected to the charging control microchip and the logic control circuit to output different power level control signals to the logic control circuit at different times; and

    a basic input/output system (BIOS) electronically connected to the logic control circuit;

    wherein the southbridge microchip and the BIOS both control the logic control circuit to output voltage signals to set or reset voltage of the two control terminals, the charging control microchip is switched to a charging mode or a data transmission mode according to the voltage of the two control terminals;

    when the electronic apparatus is shut down, the southbridge microchip outputs the power level control signal to the logic control circuit, thereby letting the charging control microchip continually charge the battery of the portable electronic device;

    the logic control circuit includes a first metal oxide semiconductor field effect transistor (MOSFET) and a second MOSFET, a gate of the first MOSFET is directly connected to the southbridge microchip, a source of the first MOSFET is directly connected to ground, a drain of the first MOSFET is directly connected to a gate of the second MOSFET, a source of the second MOSFET is directly connected to ground, a drain of the second MOSFET is directly connected to the BIOS and the two control terminals;

    the southbridge microchip is operable to output the power level control signal to the gate of the first MOSFET, and the BIOS is operable to output a general purpose input/output (GPIO) control signal to the drain of the second MOSFET;

    the power level control signal is logic 1 in response to a sleep mode state of the electronic apparatus;

    when the GPIO control signal is logic 1, the two control terminals are both set to logic 1, the charging control microchip is switched to the data transmission mode to exchange data with the portable electronic device.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×