Galvanically Isolated IGBT Gate Driver with Advanced Protections and A Fault Detection and Reporting Method

This paper presents a method for detecting and reporting fault signals that can occur in the normal functionality of galvanically isolated Insulated Gate Bipolar Transistor (IGBT) gate drivers with advanced protection circuits. The method provides robust transmission of Under Voltage Lock Out (UVLO) and Desaturation (DESAT) events, while the protection methods, such as soft shutdown and Active Miller Clamp (AMC), prevent improper functionality that can damage the IGBT. The technique introduces a block that prioritizes and encodes the error signals in a manner that allows area and cost minimization, as well as reducing the power consumption of the gate driver. The proposed circuit was verified by means of simulations, and implemented in a standard 0.25 mu m CMOS BCD technology, as part of a galvanically isolated IGBT gate driver. Experimental results highlight proper reporting of UVLO/DESAT faults and validate the functionality of the protection functions.