A power adapter, configured to be coupled to a communication interface of an electronic device via a communication interface thereof and to charge a battery in the electronic device, wherein the power adapter comprises an EMI filter circuit, a high-voltage rectifier and filter circuit, an isolation transformer, an output filter circuit, and a voltage tracking and control circuit, and the power adapter further comprises a power circuit, a main control circuit, a potential regulation circuit, a current detection circuit, a voltage detection circuit and an output switch circuit;
- an input terminal of the power circuit is coupled to a secondary terminal of the isolation transformer;
- a power terminal of the main control circuit, a power terminal of the potential regulation circuit, and a power terminal of the current detection circuit are jointly coupled to an output terminal of the power circuit, a high-potential terminal of the main control circuit and a high-potential terminal of the potential regulation circuit are both coupled to a positive output terminal of the output filter circuit, a potential regulation terminal of the potential regulation circuit is coupled to the voltage tracking and control circuit;
- a direct current input terminal of the current detection circuit is coupled to a positive output terminal of the output filter circuit;
- a current detection feedback terminal of the current detection circuit is coupled to a current detection terminal of the main control circuit;
- a clock output terminal and a data output terminal of the main control circuit are coupled to a clock input terminal and a data input terminal of the potential regulation circuit;
- a first detection terminal and a second detection terminal of the voltage detection circuit are coupled to a direct current output terminal of the current detection circuit and a negative output terminal of the output filter circuit respectively, a first output terminal and a second output terminal of the voltage detection circuit are coupled to a first voltage detection terminal and a second voltage detection terminal of the main control circuit respectively;
- an input terminal of the output switch circuit is coupled to the direct current output terminal of the current detection circuit;
- an output terminal of the output switch circuit is coupled to a third detection terminal of the voltage detection circuit;
- a ground terminal of the output switch circuit is coupled to a negative output terminal of the output filter circuit;
- a controlled terminal and a power terminal of the output switch circuit are coupled to a switch control terminal of the main control circuit and the secondary terminal of the isolation transformer respectively;
- each of a negative output terminal of the output filter circuit, the output terminal of the output switch circuit, and a first communication terminal and a second communication terminal of the main control circuit is coupled to the communication interface of the power adapter;
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- when the power adapter is charging the battery after the power adapter is powered on or reset, the main control module controls the output switch module to switch off a direct current output of the power adapter, the voltage detection module detects the output voltage of the power adapter and feeds back a voltage detection signal to the main control module, and the main control module determines whether the output voltage of the power adapter is greater than a voltage threshold according to the voltage detection signal;
- if the output voltage of the power adapter is greater than the voltage threshold, the main control module continues to judge the output voltage of the power adapter;
- if the output voltage of the power adapter is not greater than the voltage threshold, the main control module controls the output switch module to switch on the direct current output of the power adapter, and drives the voltage tracking and control circuit through the potential regulation module to set an output voltage of the isolation transformer as a conventional output voltage;
- the current detection module detects the output current of the power adapter, and feeds back a current detection signal to the main control module;
- when the main control module determines according to the current detection signal that the output current of the power adapter is within a conventional current range for a preset time interval, the main control module performs a quick charge inquiry communication with the electronic device, and after the electronic device sends a quick charge command to the main control module, the main control module drives the voltage tracking and control circuit through the potential regulation module to adjust the output voltage of the isolation transformer, according to battery voltage information fed back by the electronic device;
- when the output voltage of the power adapter meets a voltage requirement for quick charge predefined by the electronic device, the main control module drives the voltage tracking and control circuit through the potential regulation module to adjust the output voltage of the isolation transformer, so that the power adapter outputs direct current according to a quick charge current value and a quick charge voltage value.