| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress the resonance in reverse recovery operation of an FWD(Free Wheeling Diode) formed of silicon carbide, which is connected to a semiconductor switching element in reverse parallel, to prevent generation of an electromagnetic noise. <P>SOLUTION: IGBTs(Insulated Gate Bipolar Transistor) 1a and 1b as semiconductor switching elements and FWDs 2a and 2b as wide bandgap devices formed of silicon carbide are connected in reverse parallel on circuit patterns 10a and 10b. Magnetic ferrite rings 7 are adhered to peripheries of the FWDs 2a and 2b so as to surround the FWDs 2a and 2b. Thereby, from an aspect of an equivalent circuit, a resistance which is an impedance component of the ferrite ring 7 is connected in series to the FWDs 2a and 2b. The resistance suppresses the resonance phenomenon generated at a reverse recovery operation of the FWDs 2a and 2b, and generation of an electromagnetic noise can be prevented. <P>COPYRIGHT: (C)2012,JPO&INPIT |
