| 摘要 |
PROBLEM TO BE SOLVED: To suppress oscillation of current waveform flowing in an IGBT, reduce the size of a semiconductor device, and to reduce the cost. SOLUTION: The semiconductor device is provided with an IGBT 3 to interrupt low-voltage current, flowing into a primary coil, a constant-voltage circuit 7 provided between an external gate terminal 1 and an external collector terminal 2, and zener diodes 4-6 for protection. The constant-voltage circuit 7 supplies a constant gate voltage to the IGBT 3 so that the saturated current value of the IGBT 3 is a predetermined limiting current value. The IGBT 3 has the saturated current value, in a range of the limiting current value of the semiconductor device. In the constant voltage circuit 7, a plurality of depression-type MOSFETs that are connected in parallel, and a diode are connected in series. Each of the depression-type MOSFETs is connected with a selection switch, and all the selection switches are connected to a selector circuit. The selector switches are opened or closed by the selector circuit at factory shipment, thereby adjusting the variance of the voltage that is produced due to the electrical characteristics on the manufacturing of the semiconductor device. COPYRIGHT: (C)2010,JPO&INPIT |
