A self-adaptive blanking time circuit for fast IGBT De-saturation Short-circuit protection

Abstract

This paper proposed a self-adaptive blanking time (SABT) circuit for fast IGBT de-saturation short-circuit detection. When IGBT normally turns on or experiences fault under load (FUL), the blanking time is implemented by detecting the variation of IGBT collector-to-emitter voltage V_CE. While when IGBT is under hard switching failure (HSF), the blanking time is determined by detecting gate voltage V_GE. The simulation with the UMC 0.6 μm 700 V technology indicates that the proposed SABT circuit can quickly detect FUL and HSF. Compared to the conventional blanking time circuit, the SABT circuit can shorten the fault detection time of FUL from 1.3 μs to 35.5 ns, while the fault detection time of HSF condition is reduced from 2.329 μs to 294 ns.