SWITCHING-BEHAVIOR IMPROVEMENT OF INSULATED GATE-CONTROLLED DEVICES

MOSFET's and insulated gate bipolar transistor (IGBT) devices are incr easingly used in electronic circuits due to both their easy driving an d ability to handle high currents and voltages at high-switching frequ encies. This paper deals with a new driver technique that allows optim ization of the switching speed, reduction of the energy losses during the switching time, and limitation of the electromagnetic interference (EMI). First, an analysis of voltage- and current-switching waveforms of gate-insulated devices is performed. Then, a method of controlling voltage and current slopes independently is shown using the ''one-cyc le'' method or a suitable adaptive-driving technique based on a phase- locked loop (PLL) approach. These techniques were adopted in order to allow correct generation of the gate signals regardless of the operati ng conditions. Finally, practical results of the proposed driving circ uit obtained using a single IGBT switch chopper are presented.