Device and method for converting input voltage to output voltage

A device for controlling a power converter which converts an input voltage to an output voltage;

• wherein the device comprises:
• a digital controller configured to obtain a driving power to perform a controlling the power converter;
• a startup circuit configured to generate a controlling voltage of the digital controller according to an instruction from the digital controller;
• wherein the digital controller is configured to obtain the driving power based on the controlling voltage when the power converter is stopped;
• wherein the controlling voltage is provided into the digital controller as the driving power when it is detected that the controlling voltage is lower than or equal to a predetermined voltage;
• wherein a first voltage is decreased by more than or equal to 10% to generate the controlling voltage, and/or, the controlling voltage is equal to a second voltage.

A method for controlling a power converter which converts an input voltage to an output voltage, wherein the method comprises:

• obtaining a first voltage by an activation terminal based on the input voltage;
• obtaining a second voltage by a controlling terminal based on the output voltage;
• and
• obtaining a driving power by a digital controller based on the first voltage and/or the second voltage, wherein the driving power is obtained at least based on the first voltage when the power converter is stopped;
• wherein the first voltage is converted to a controlling voltage of the digital controller, and the controlling voltage is provided into the digital controller as the driving power when it is detected that the controlling voltage is lower than or equal to a predetermined voltage;
• wherein the first voltage is decreased by more than or equal to 10% to generate the controlling voltage, and/or, the controlling voltage is equal to the second voltage.