Power converter with over temperature protection compensation
A power converter with over temperature protection compensation includes a main conversion unit, a primary-side control unit, a secondary-side control unit, a secondary detection circuit, and an over temperature adjustment circuit. The secondary-side control unit obtains a secondary voltage change value through the secondary detection circuit, and the secondary-side control unit correspondingly provides a current change value to the over temperature adjustment circuit according to the secondary voltage change value. The over temperature adjustment circuit provides a temperature control voltage according to the current change value so that the secondary-side control unit determines whether an over temperature protection is activated according to the temperature control voltage.
1. A power converter with over temperature protection compensation, comprising:
a main conversion unit having a primary side and a secondary side, the primary side coupled to an input voltage, the secondary side coupled to a secondary rectifier filter circuit,
a primary-side control unit coupled to the primary side,
a secondary-side control unit coupled to the primary-side control unit,
a secondary detection circuit coupled to the secondary side, and
an over temperature adjustment circuit coupled to the secondary-side control unit,
wherein the secondary-side control unit is configured to obtain a secondary voltage change value through the secondary detection circuit, and the secondary-side control unit is correspondingly configured to provide a current change value to the over temperature adjustment circuit according to the secondary voltage change value; the over temperature adjustment circuit is configured to provide a temperature control voltage according to the current change value so that the secondary-side control unit is configured to determine whether an over temperature protection is activated according to the temperature control voltage;
wherein the secondary-side control unit is configured to provide the secondary voltage change value according to a handshaking signal provided by a load.
2. The power converter in claim 1 , wherein the secondary-side control unit is configured to turn off the main conversion unit through the primary-side control unit to activate the over temperature protection.
3. The power converter in claim 1 , further comprising:
a protection switch coupled to the secondary rectifier filter circuit,
wherein the secondary-side control unit is configured to turn off the protection switch to activate the over temperature protection.
4. The power converter in claim 1 , wherein the over temperature adjustment circuit comprises a temperature control resistor, the temperature control resistor is configured to generate a temperature control resistance according to an ambient temperature, and the current change value flows through the temperature control resistance to generate the temperature control voltage.
5. The power converter in claim 1 , wherein the secondary-side control unit comprises a comparison unit; when the comparison unit is configured to determine that the temperature control voltage is less than a reference voltage, the secondary-side control unit is configured to activate the over temperature protection.
6. The power converter in claim 1 , wherein the input voltage is higher, the current change value provided by the secondary-side control unit is higher, and the input voltage is lower, the current change value provided by the secondary-side control unit is lower.