| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress an increase in the forward drop voltage of a diode in a semiconductor device constructed using a reverse conducting IGBT chip. <P>SOLUTION: A diode 5c for monitoring a current passing through a main diode 5b is mounted on a semiconductor chip 5 in which IGBT 5a and the main diode 5b are connected in reverse-parallel with each other. The diode is connected in parallel with the main diode 5b through an external resistor 9. When the voltage across the external resistor 9 is lower than a predetermined reference voltage value, a back-flow mode determining means 7 determines that the present mode is back-flow mode in which a current flows back through the main diode 5b. An interruption circuit 3 interrupts a driving signal sent out from an input circuit 2 to a drive circuit 4. Thus, when in back-flow mode, the IGBT 5a is not turned on and thus an increase in the forward drop voltage of the main diode 5b can be suppressed. <P>COPYRIGHT: (C)2008,JPO&INPIT |
