IEGT design criterion for reducing EMI noise [injection enhancement gate transistor]

The EMI noise of an IGBT/IEGT (injection enhancement gate transistor) circuit is significantly reduced by introducing a new device design criterion. The design criterion improves dV_CE/dt controllability during the IEGT turn-on transient without sacrificing the featured low saturation voltage of the IEGT structure. The perfectly floating p-well region, as the criterion, prevents the undesirable V_GE overshoot and the resultant uncontrollable dV_CE/dt. The design criterion has been applied to a 1200 V ultra thin PT-IEGT, and low noise turn-on characteristics have been experimentally obtained. IEGTs with the new criterion enable low noise operation and precise gate control, which are suitable for active gate drive.