1300 V, 2 ms pulse inductive load switching test circuit with 20 ns selectable crowbar intervention

A non destructive inductive load switching (ILS) test apparatus with the capability of delivering high current pulses with a maximum 2 ms duration under a 1300 V supply is presented in this work. The system is also provided with a fast crowbar whose intervention is programmable with a 20 ns resolution and is intended to perform tests on power devices driving generic inductive loads. This kind of test is commonly used for quality control and prototype verification in power devices industry [Busatto G, Cascone B, Fratelli L, Balsamo M, Iannuzzo F, Velardi F. Non-destructive high temperature characterization of high-voltage IGBTs. Microelectron Reliab 2002;42(9–11):1635–40]. The high resolution crowbar intervention allows an immediate steering of the current away from the Device Under Test (DUT) after the failure event. In this way device damage is minimized so as to have a better understanding of the exact position of the failure, an essential parameter to infer the reasons that caused it [Trivedi M, Shenai K. Failure mechanisms of IGBTs under short-circuit and clamped inductive switching stress. IEEE Trans Power Electron 1999;14(1):108–16; Breglio G, Irace A, Riccio M, Spirito P, Hamada K, Nishijima T, et al. Detection of localized UIS failure on IGBTs with the aid of lock-in thermography. Microelectron Reliab 2008;48(8–9):1432–4].