Input range expander for power supplies

摘要

An electro-magnetic interference (EMI) filter having a boost mode amplifier integrated therewith is provided. The boost mode amplifier utilizes the filtering inductors of the EMI filter as energy storage devices to control the input voltage supplied to a DC-to-DC power converter. A controller is also provided for selectively activating the boost mode amplifier, maintaining the input voltage provided to the converter within a predetermined operating range.

主权项

1. An electromagnetic interference filter comprising:
a filtering circuit for filtering an input voltage comprising a first inductor arranged in series on an input voltage line and a second inductor arranged in series on a voltage return line; a boost mode converter integrated into the filter, the converter comprising a switching element operative to selectively charge and discharge the first and second inductors; and a controller operatively connected to the switching element, the controller configured to measure an output voltage of the filtering circuit and enable the boost mode converter if the measured output voltage falls below a predetermined lower voltage limit and disable the boost mode converter if the measured output voltage rises above a predetermined upper voltage limit, wherein the predetermined upper voltage limit and lower voltage limit are selected to fall within an operating voltage range of a power converter supplied by the input voltage such that the controller is configured to prevent the shut down of the power converter.