U.S. Philips Corporation

Thomas D&uuml;rbaum

Hubert C Raets

Pieter Jan Mark Smidt

Georg Sauerl&auml;nder

The invention relates to a converter comprising switching elements for chopping a direct voltage, in which turn-on phases of the switching elements alternate with one another, and comprising a circuit arrangement with resonant circuit elements processing the chopped direct voltage and serving for the supply of an output voltage. To improve such a converter in such a way that zero voltage switching (ZVS) can be ensured in an extended range of converter operations with possibly inexpensive converter modifications, it is proposed that the length of the dead-time phases, which are present between two consecutive turn-on phases and during which the switching elements are turned off, is automatically adapted so that switching losses, which occur particularly when the switching elements are turned on, can be minimized.

Converter comprising resonant circuit elements

A multimode switched-mode power supply operates in a first control mode when the output power supplied is lower than a predetermined value, and in a second control mode when the output power supplied is higher than said predetermined value. The switched-mode power supply comprises a series arrangement of a switch (S ) and an inductor (L; Lp), the series arrangement being coupled to receive a DC input voltage (Vin). A control circuit (CC) controls the on and/or off times of the switch (S ) to generate a periodical inductor current (Ip) in the inductor (L; Lp). In the first control mode, a peak value of the inductor current (Ip) is substantially constant, independent of the power supplied. The substantially constant peak value is substantially equal to a peak value of the inductor current (Ip) at an instant when the second control mode is altered into the first control mode.

Growing community of inventors

Aachen, Germany

Thomas Dürbaum

Growing community of inventors

Aachen, Germany

Thomas D&uuml;rbaum

Thomas Dürbaum