Netpower Technologies, Inc.

Lucent Technologies Inc.

Ning Sun

Hengchun Mao

Yimin Jiang

Feng Lin

Raymond W Pilukaitis

Circuit and method for controlling circuitry in a power converter device during a soft-start process is provided. Synchronous rectifier control circuitry is adapted to gradually apply a gate drive signal derived from the main switch of the power converter device to a freewheeling synchronous rectifier of the switching circuitry during the soft-start process. The control circuitry gradually releases the amplitude or the pulse-width of the gate drive signal to the freewheeling synchronous rectifier to avoid a large duty ratio in the synchronous rectifier during start-up so that a negative current does not build up in the output inductor.

Soft start for a synchronous rectifier in a power converter

A power distribution system is provided including current sharing circuitry, current sensing and over-current protection. The system includes a plurality of power converter modules each having a current sharing signal terminal on an input side and power output terminals on an output side, the corresponding power output terminals of the several modules being connected together and adapted to power a common load; an interconnecting signal bus coupled across the current sharing signal terminals on the input side; a plurality of feedback circuits, each of which is associated with one of said modules, each feedback circuit including a comparator (error amplifier) for comparing a feedback voltage on the output side with a reference voltage to provide an error signal to the input side; the error signal conditioned to provide a current command signal to said signal bus, wherein the signal bus provides a common current command signal to drive the power converter modules.

Plural power converters with individual conditioned error signals shared on a current sharing bus

For use with a controller, couplable to a network of first and second comparators, that disables a power converter an actual output current thereof exceeds a threshold output current, an integrated protection circuit and method of operating the same. In one embodiment, the integrated protection circuit includes: (1) a sensor that senses an actual input voltage of the power converter and (2) an isolation circuit, coupled to the first comparator, that selectively decouples the first comparator from the controller, the second comparator causing the controller to disable the power converter when the actual input voltage falls below a threshold input voltage thereby allowing the protection circuit to provide both overcurrent and undervoltage protection.

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Plano, TX, United States of America

Ning Sun