The dV / dt capability of field-controlled thyristors

A detailed analysis of the
dV/dt
capability of field-controlled thyristors is presented. It is demonstrated for the first time that
dV/dt
induced turn-on can occur in these devices due to gate debiasing as a result of capacitive gate current flow if a large series gate resistance is present in the circuit. A theoretical analysis of the
dV/dt
capability is presented based upon this mechanism which predicts that the
dV/dt
capability will decrease inversely with increasing gate series resistance at low values and become independent of the gate series resistance at very high values. The quantitative calculations of the
dV/dt
capability that have been made by using this theory are in very good agreement with measurements taken on asymmetrical field-controlled thyristors fabricated from wafers of various thickness. The results obtained in this study allow the conclusion that the
dV/dt
capability of field-controlled thyristors are superior to that of conventional thyristors.