| 摘要 |
PURPOSE:To increase the dv/dt rating by short-circuiting a latchup preventing resistor when a gete-emitter, voltage is below a prescribed value when an IGBT (Insulated Gate Bipolar Mode Transistor) is turned off. CONSTITUTION:A transistor (TR) 9a is turned on when the condition of E-Ez>=EGE exists, where E is the power supply voltage, Ez is a Zener voltage of a Zener diode 8 and EGE is a voltage of the IGBT 1 between a gate and emitter. Then a TR 9b is turned on and the latchup preventing resistor 2 is short-circuitted. Thus, even if a voltage with a large dv/dt is applied to the collector-emitter of the IGBT1, the gate-emitter voltage rise is suppressed and malfunction such as mis-turning-on or the like is prevented. |
