Self-powered synchronous rectifiers
AssigneeKoninklijke Philips Electronics N.V.
InventorRaymond J. Grover
Life of this patent
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Abstract
A two-terminal self-powered synchronous rectifier (ASR) is provided, together with two-terminal or three-terminal packaged devices that can replace an output diode rectifier (D) in a switched mode power supply. The synchronous rectifier comprises a field-effect transistor (M) having its source-drain path in a first arm (11) between the two rectifier terminals (A,K), normally a parallel diode (BD) in a second arm (12), a gate-control circuit (GC) connected to a gate electrode (g) of the transistor (M) for switching the transistor (M) synchronously on and off in accordance with voltage reversal at the two rectifier terminals (A,K), and a charge pump (C,R; C,R,C2,R2) in a third parallel arm for powering the control circuit from the power signal being rectified by the rectifier.
Claims11
A two-terminal synchronous rectifier comprising a field-effect transistor having its source-drain path in a first arm between the two rectifier terminals, and a gate-control circuit connected to a gate electrode of the transistor for switching the transistor synchronously in accordance with voltage reversal at the two rectifier terminals, wherein the synchronous rectifier includes a further parallel arm comprising a charge pump that is energized by a voltage difference between the two rectifier terminals, the gate-control circuit being powered from the charge pump.
A two-terminal self-powered synchronous rectifier device comprising a two-terminal package within which a field-effect transistor, parallel diode, gate-control circuit and charge pump are accommodated, wherein an output of the gate-control circuit is connected within the device package to a gate electrode of the transistor for switching the transistor, and wherein the charge-pump, the parallel diode and the source-drain path of the transistor are connected between the two terminals of the device package in a parallel configuration, and the charge pump has an output that powers the gate-control circuit for switching the transistor.
Dependencies are inferred from the claim text.