Dynamic protection circuit, power supply circuit and control method thereof

A power supply circuit comprising:

• a conversion circuit configured to convert an external power into a direct current (DC) power;
• a processing circuit configured to process the DC power to generate an output voltage;
• a switch configured to transmit the output voltage;
• and
• a dynamic protection circuit comprising:
• an adjustment circuit configured to adjust the output voltage based on the predetermined value;
• a detection circuit configured to detect whether the output voltage is higher than an upper-limit value or lower than a lower-limit value;
• a control circuit configured to change the predetermined value and disable the detection circuit while the predetermined value is being changed;
• and
• a counter circuit configured to start to adjust a count value in response to the detection circuit being disabled,
• wherein:
• in response to the counter circuit adjusting the count value, the control circuit adjusts the upper-limit value and the lower-limit value to be proportional to the output voltage, and
• in response to the count value being equal to a target value, the counter circuit enables the detection circuit.

A control method comprising:

• generating an output voltage based on a predetermined value;
• changing the predetermined value;
• disabling an overvoltage protection circuit and an undervoltage protection circuit, wherein the overvoltage protection circuit determines whether the output voltage is higher than an upper-limit value, and the undervoltage protection circuit determines whether the output voltage is lower than a lower-limit value;
• performing a timing operation;
• adjusting the upper-limit value and the lower-limit value;
• in response to the duration of the timing operation reaching a target value:
• stopping the adjustment of the upper-limit value and the lower-limit value;
• and
• stopping the disabling of the overvoltage protection circuit and the undervoltage protection circuit.