| 摘要 |
<p>PURPOSE: To surely cut off a load current and prevent breakdown, by connecting the attached emitter, the main emitter and the gate of a voltage driven type element of the lowest saturation voltage with the gate and the source of an MOSFET, and the anode of a diode which constitute an overcurrent protection circuit, respectively. CONSTITUTION: An overcurrent protection circuit 8 consists of an MOSFET 15, a diode 16 and a resistor 17. An attached emitter 4 for current detection of an IGBT 2 of low ON-voltage out of a plurality of IGBT's is connected with the gate 9 of the MOSFET 15 in the overcurrent protection circuit 8. The gate 6 and the main emitter 5 of the IGBT 2 are connected with the anode 11 of the diode 16 and the source 10 of the MOSFET 15, respectively. A resistor 15 is connected between the gate 9 and the source 10 of the MOSFET 15, whose drain 18 is connected with the cathode 19 of the diode 16. Thus an overcurrent protection circuit 8 is constituted. A plurality of IGBT's are connected in parallel, and operate as a large capacity semiconductor device.</p> |
