Power-One Limited

Osram Sylvania Inc.

Pai Capital LLC

Donald Richard Caron

David Williams

Ram Ramabhadran

There is disclosed a power conversion circuit comprising a transformer having a primary side driven by an input section and a secondary side connected to first and second self-driven synchronous rectifiers. A shutdown section includes a control section adapted to detect a predetermined condition and means for shorting a winding of the transformer upon detection of the predetermined condition.

Self driven synchronous rectifier shutdown circuit and method

There is disclosed a power conversion circuit including self synchronous rectifiers and a rapid shutdown section. When power is removed from the power conversion circuit, the rapid shutdown section prevents self oscillation of the self synchronous rectifiers. As a result, power is not drawn from the output and dissipated in the power conversion circuit.

Primary side turn-off of self-driven synchronous rectifiers

An unregulated DC-to-DC power converter suitable for intermediate bus voltage converter applications includes synchronous rectifiers that are driven efficiently to provide faster transition time and reduced loss. The DC-to-DC power converter comprises a transformer having a primary winding and at least first and second secondary windings. An input circuit is coupled to the primary winding and is adapted to apply an alternating polarity square wave voltage to the primary winding. An output circuit comprising an output filter is coupled to a tap of the first secondary winding. The output filter provides a DC output voltage. A first synchronous rectifier is coupled to a first end of the first secondary winding and a second synchronous rectifier is coupled to a second end of the first secondary winding. The second secondary winding has a first end coupled to a control terminal of the first synchronous rectifier and a second end coupled to a control terminal of the second synchronous rectifier. A first snubber circuit is coupled between the control terminal of the first synchronous rectifier and the second end of the first secondary winding. A second snubber circuit is coupled between the control terminal of the second synchronous rectifier and the first end of the first secondary winding. The first and second snubber circuits provide faster transition of the first and second synchronous rectifiers, respectively, between on and off states.

Unregulated DC-DC converter having synchronous rectification with efficient gate drives

An electronic ballast circuit (FIG. ) includes a voltage-regulated DC power source and an H-bridge having a plurality of transistors (Q , Q , Q , Q ). The circuit operates a high intensity discharge lamp ( ). A regulating circuit electrically connected to the transistors regulates the peak current flowing through the H-bridge by discharging a parasitic capacitance (C parasitic).

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Windham, NH, United States of America

Donald Richard Caron