Abstract: The present disclosure relates to solutions for operating a flyback converter comprising an active clamp. The flyback converter comprises two input terminals and two output terminals. A first electronic switch and the primary winding of a transformer are connected in series between the input terminals. An active clamp circuit is connected in parallel with the primary winding. The active clamp circuit comprises a series connection of a clamp capacitor and a second electronic switch. A third electronic switch and the secondary winding of the transformer are connected in series between the two output terminals. In particular, the present disclosure relates to solutions for switching the first, second and third electronic switch in order to achieve a zero-voltage switching of the first electronic switch.

Abstract: An electronic device includes a circuit board that manages supply of electricity to the electronic device. The circuit board includes an integrated circuit and an external capacitor coupled to a supply terminal of the circuit board. During a startup operation of the integrated circuit, the integrated circuit supplies a first charging current to charge the capacitor to a supply voltage value. The circuit board includes a boost circuit that receives a portion of the first charging current and outputs a second charging current that augments charging of the capacitor. The second charging current is an amplification of the first charging current. The integrated circuit enables operation of the electronic device after the capacitor is charged to the supply voltage value.

Abstract: An embodiment provides a circuit including a transformer having a primary winding coupled to an input port configured to receive an input voltage and a secondary winding configured to provide an output voltage at an output port, controller circuitry configured to switch on and off a current through the primary winding so that energy is transferred to the secondary winding while switching and supply circuitry connected to the controller circuitry, wherein the supply circuitry is coupled to an auxiliary winding of the transformer and configured to provide a supply voltage for the controller circuitry.

Abstract: The present disclosure relates to solutions for operating a flyback converter comprising an active clamp. The flyback converter comprises two input terminals and two output terminals. A first electronic switch and the primary winding of a transformer are connected in series between the input terminals. An active clamp circuit is connected in parallel with the primary winding. The active clamp circuit comprises a series connection of a clamp capacitor and a second electronic switch. A third electronic switch and the secondary winding of the transformer are connected in series between the two output terminals. In particular, the present disclosure relates to solutions for switching the first, second and third electronic switch in order to achieve a zero-voltage switching of the first electronic switch.

Abstract: An embodiment provides a circuit including a transformer having a primary winding coupled to an input port configured to receive an input voltage and a secondary winding configured to provide an output voltage at an output port, controller circuitry configured to switch on and off a current through the primary winding so that energy is transferred to the secondary winding while switching and supply circuitry connected to the controller circuitry, wherein the supply circuitry is coupled to an auxiliary winding of the transformer and configured to provide a supply voltage for the controller circuitry.

Abstract: The present disclosure relates to solutions for operating a flyback converter comprising an active clamp. The flyback converter comprises two input terminals and two output terminals. A first electronic switch and the primary winding of a transformer are connected in series between the input terminals. An active clamp circuit is connected in parallel with the primary winding. The active clamp circuit comprises a series connection of a clamp capacitor and a second electronic switch. A third electronic switch and the secondary winding of the transformer are connected in series between the two output terminals. In particular, the present disclosure relates to solutions for switching the first, second and third electronic switch in order to achieve a zero-voltage switching of the first electronic switch.

Abstract: An electronic device includes a circuit board that manages supply of electricity to the electronic device. The circuit board includes an integrated circuit and an external capacitor coupled to a supply terminal of the circuit board. During a startup operation of the integrated circuit, the integrated circuit supplies a first charging current to charge the capacitor to a supply voltage value. The circuit board includes a boost circuit that receives a portion of the first charging current and outputs a second charging current that augments charging of the capacitor. The second charging current is an amplification of the first charging current. The integrated circuit enables operation of the electronic device after the capacitor is charged to the supply voltage value.

Abstract: An electronic device includes a circuit board that manages supply of electricity to the electronic device. The circuit board includes an integrated circuit and an external capacitor coupled to a supply terminal of the circuit board. During a startup operation of the integrated circuit, the integrated circuit supplies a first charging current to charge the capacitor to a supply voltage value. The circuit board includes a boost circuit that receives a portion of the first charging current and outputs a second charging current that augments charging of the capacitor. The second charging current is an amplification of the first charging current. The integrated circuit enables operation of the electronic device after the capacitor is charged to the supply voltage value.

Abstract: A control circuit is configured to control a power factor correction (PFC) pre-regulator including a power switch and being configured to operate in a transition mode of operation and a valley-skipping mode of operation. The control circuit generates a drive signal to control a switching of the power switch based on a current threshold. A current threshold generator in the control circuit is configured to modulate the current threshold as a function of a number of valleys skipped in the valley-skipping mode of operation.

Abstract: An electronic device includes a circuit board that manages supply of electricity to the electronic device. The circuit board includes an integrated circuit and an external capacitor coupled to a supply terminal of the circuit board. During a startup operation of the integrated circuit, the integrated circuit supplies a first charging current to charge the capacitor to a supply voltage value. The circuit board includes a boost circuit that receives a portion of the first charging current and outputs a second charging current that augments charging of the capacitor. The second charging current is an amplification of the first charging current. The integrated circuit enables operation of the electronic device after the capacitor is charged to the supply voltage value.

Abstract: A control circuit is configured to control a power factor correction (PFC) pre-regulator including a power switch and being configured to operate in a transition mode of operation and a valley-skipping mode of operation. The control circuit generates a drive signal to control a switching of the power switch based on a current threshold. A current threshold generator in the control circuit is configured to modulate the current threshold as a function of a number of valleys skipped in the valley-skipping mode of operation.

Abstract: The present disclosure relates to solutions for operating a flyback converter comprising an active clamp. The flyback converter comprises two input terminals and two output terminals. A first electronic switch and the primary winding of a transformer are connected in series between the input terminals. An active clamp circuit is connected in parallel with the primary winding. The active clamp circuit comprises a series connection of a clamp capacitor and a second electronic switch. A third electronic switch and the secondary winding of the transformer are connected in series between the two output terminals. In particular, the present disclosure relates to solutions for switching the first, second and third electronic switch in order to achieve a zero-voltage switching of the first electronic switch.

Abstract: A method and apparatus for controlling a power converter are provided. In the method and apparatus, switching from a first phase to a second phase is delayed until it is determined that both a tank current signal of the converter goes below a tank current threshold and the converter has been in the first phase for more than a first minimum time period. Then the converter determines if a resonant capacitor voltage has fallen below a first resonant capacitance voltage threshold and if a tank current signal goes above a tank current threshold. The converter switches from the first phase to the second phase in response to determining at least one of: the resonant capacitor voltage has fallen below the first resonant capacitance voltage threshold and the tank current signal goes above the tank current threshold. The converter is additionally operated in third and fourth states.

Abstract: A method and apparatus for controlling a power converter are provided. In the method and apparatus, switching from a first phase to a second phase is delayed until it is determined that both a tank current signal of the converter goes below a tank current threshold and the converter has been in the first phase for more than a first minimum time period. Then the converter determines if a resonant capacitor voltage has fallen below a first resonant capacitance voltage threshold and if a tank current signal goes above a tank current threshold. The converter switches from the first phase to the second phase in response to determining at least one of: the resonant capacitor voltage has fallen below the first resonant capacitance voltage threshold and the tank current signal goes above the tank current threshold. The converter is additionally operated in third and fourth states.