Wearable electronic device, charging device and operation method thereof

Abstract

A wearable electronic device, a charging device, and a method of operating the same are proposed. The charging device includes a power generation circuit and a dummy load circuit. The power generation circuit receives power from an external device and generates system power and charging power based on the supplied power. The dummy load circuit is coupled to the terminal of the power generation circuit that generates the system power or charging power, and provides a dummy load based on the magnitude of the charging current provided by the charging power.

Claims

1. A charging device for a wearable electronic device, comprising: A power generation circuit receives a power supply from an external device and generates a system power supply and a charging power supply based on the power supply. And a dummy load circuit coupled to the endpoint of the power generation circuit that generates the system power or the charging power, providing a dummy load according to the magnitude of a charging current provided by the charging power.

2. The charging device as claimed in claim 1, wherein the virtual load circuit comprises: A switch, controlled by a control signal to be turned on or off; And a load element coupled between the switch and a reference voltage terminal to provide the dummy load.

3. The charging device as described in claim 2, further comprising: A controller sets a threshold current based on the expected minimum supply current of the mobile power supply plus the system current of the system power supply; When the charging current provided by the charging power supply is less than the threshold current, the control signal is enabled to turn on the switch.

4. The charging device as claimed in claim 2, wherein the resistance value provided by the load element is set by dividing (the voltage value of the system power supply) by (the difference between a minimum supply current of the power supply and the system current of the system power supply and the minimum effective charging current of the battery).

5. The charging device as claimed in claim 1, wherein the external device is a mobile power supply.

6. A method for operating a charging device for a wearable electronic device, comprising: A power generation circuit is provided to receive a power supply from an external device and to generate a system power supply and a charging power supply based on the power supply. A dummy load circuit is provided to be coupled to the endpoint of the power generation circuit that generates the system power supply or the charging power supply; and a dummy load is provided according to the magnitude of a charging current provided by the charging power supply.

7. The operating method as described in claim 6 further includes: A switch and a load element are provided to be coupled in series between the terminal of the power generation circuit that generates the system power or the charging power and a reference voltage terminal. The switch is controlled by a control signal to be turned on or off; and when the switch is turned on, the load element provides the dummy load to the endpoint of the power generation circuit that generates the system power or the charging power.

8. The operating method as described in claim 7 further includes: A threshold current is set by adding the expected minimum supply current of the mobile power supply to the system current of the system power supply. And when the charging current provided by the charging power supply is less than the threshold current, the control signal is enabled to turn on the switch.

9. The operating method as described in claim 8, wherein the threshold current is greater than the minimum effective charging current.

10. The operating method as described in claim 7 further includes: The resistance value of the load element is set by dividing the voltage value of the system power supply by the difference between the minimum supply current of the power supply and the system current of the system power supply and the minimum effective charging current of the battery.

11. A wearable electronic device, comprising: The charging device as described in claim 1; It also includes a battery and a power management circuit, the battery receiving the charging power for charging, and the power management circuit receiving the system power as an operating power source.

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