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Simple turn-off description of Trench- Field-stop IGBT - IGBT3/3.3 kV

New IGBT generations, i.e. Trench-Field-stop devices show significant difference in control characteristics in comparison to Power MOSFETs. The reason is the large amount of stored charge, which builds up in the conduction mode. In this paper this storage effect is described by an additional element in an equivalent circuit, i.e. a capacitance at the output. A simple equivalent circuit contains the output characteristics, CGC-, CGE-, and the new CCEcapacitance. This circuit describes principal switching and control characteristics. Characterization of these elements is done by special test configurations, which allow excluding parasitic capacitance of the package. As an additional outcome of the work the stored charge IGBT3 /3.3kV and its dependence on conduction time is received and will be presented. The Turn off of standard power MOSFETs under inductive load starts with a drop of gate voltage to the threshold for the actual load current. Then the gate voltage stays at that level while the drain voltage is rising and the drain current continues to flow. When the drain voltage reaches the DC-bus voltage the drain current starts to fall controlled by the gate voltage, now drop from the threshold level (Miller plateau) to the off state. The turn-off is completely controlled by the gate voltage. Super-Junction MOSFETs can differ from this behavior.

• 560.96 KB
• May 31, 2012