Isolated converter with constant voltage mode and constant current mode and control method thereof

An isolated converter with a constant voltage mode and a constant current mode, the isolated converter comprising:

• a transformer comprising
• a primary winding on a primary side;
• and
• a secondary winding on a secondary side;
• a main switch on the primary side, the main switch being connecting in series with the primary winding;
• a driver on the primary side, the main switch being controllably turned on or off by the driver to control a current flowing through the primary winding;
• a controller on the secondary side, the controller comprising:
• a constant current control unit generating a voltage adjustment signal according to a current feedback signal representing an output current, the voltage adjustment signal being applied to adjust a reference voltage or a voltage feedback signal representing an output voltage, to generate an adjusted reference voltage or an adjusted voltage feedback signal;
• a voltage comparator comparing the voltage feedback signal with the adjusted reference voltage, or the adjusted voltage feedback signal with the reference voltage, to generate a comparison signal;
• and
• a control logic unit generating a trigger signal according to the comparison signal;
• and
• an isolator transmitting the trigger signal from the secondary side to the driver on the primary side.