Patent ID: 6285235
Filing Date: 2001-09-04
Classification: H02M,H03K

Abstract:
A gate control circuit for turning on and off an insulated gate semiconductor device having a collector terminal, an emitter terminal and a gate terminal, comprising:a first DC power source coupled to said gate terminal via a first switch and configured to apply a positive voltage to said gate terminal in order to turn on said insulated gate semiconductor device when said first switch is turned on and a second switch is turned off;a second DC power source coupled to said gate terminal via said second switch and configured to apply a negative voltage to said gate terminal in order to turn off said insulated gate semiconductor device when said second switch is turned on and said first switch is turned off;a parallel circuit of a diode and a capacitor coupled in series to said second switch; anda turn off assist circuit configured to produce a negative charge on said capacitor to assist in turning off said insulated gate semiconductor devices;wherein said turn off assist circuit comprises a third DC power source coupled in series with a third switch.