Transformerless capacitive coupling of gate signals for seriesoperation of power MOS devices

摘要

A reliable configuration for triggering a series string of powernmetal oxide semiconductor (MOS) devices without the use of transformerncoupling is presented. A capacitor is inserted between the gate andnground of each metal oxide semiconductor field effect transistorn(MOSFET), except for the bottom MOSFET in the stack. Using a singleninput voltage signal to trigger the bottom MOSFET, a voltage divisionnacross the network of device capacitance and inserted capacitancesntriggers the entire series stack reliably. Design formulas are presentednand simple circuit protection is discussed. Simulation shows reliablenoperation and experimental verification is presented, Application of thenmethod is applied to series insulated gate bipolar transistors (IGBTs)