Nxp B.v.

Koninklijke Philips Corporation N.v.

Alfred Grakist

Hans Halberstadt

Adrianus W Ludikhuize

Frans Pansier

Ben Verhoeven

Jan-Harm Nieland

Johannes H H A Egbers

Embodiments of a power converter are disclosed. In an embodiment, the power converter comprises a power factor correction (PFC) stage circuit, an emulation circuit and a controller. The PFC stage circuit is configured to produce an output signal on an output terminal. The PFC stage circuit includes an inductor coupled between a rectifier and the output terminal and a switch coupled to the inductor. The emulation circuit is connected to the PFC stage circuit to generate an emulated current that corresponds to current through the inductor of the PFC stage circuit. The emulated current is generated based on a voltage signal at a node between the inductor and the output terminal and a sensed current at a sense resistor connected to the rectifier. The controller is connected to the emulation circuit to receive the emulated current and generate a control signal for the switch of the PFC stage circuit based on the emulated current.

Power converter control using current reconstruction of power factor correction inductor current

This invention relates to improved methods of preventing MOSFET damage in a resonant switched mode power converter () by preventing or limiting capacitive mode operation. A combination of response actions (respectively delaying MOSFET switch-on, adjusting switching phase, forcing a switch-on, and increasing frequency) is utilized. In the preferred embodiment, the voltage slope at the half-bridge node () is monitored, and in alternative embodiments the same or similar set of response actions is triggered by monitoring different signals, including: the resonant current polarity at switch-off or after the non-overlap time; the voltage of the to-be-switched-on' switch; and the voltage of the 'just-switched-off' switch.

Control of a half resonant converter for avoiding capacitive mode

The present invention provides a driver circuit with load discharge detection particularly suitable for use with electro-luminescence (EL) lamps. The driver circuit determines the moment at which the load has been discharged by a defined discharge current. This information is used to start the new charging cycle of the load. The discharge time adapts itself to different load sizes or load voltages. Also, a minimum amount of time is used to discharge the load, so that a maximum amount of time is available for charging the load at a predetermined frequency. As a result, a higher performance can be achieved.

Driver circuit with load discharge detection

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Oosterbeek, Netherlands

Alfred Grakist