Gate Driver IC with Fully Integrated Overcurrent Protection Function by Measuring Gate-to-Emitter Voltage During IGBT Conduction

Abstract

To achieve low-cost overcurrent protection for IGBTs without using external components such as high-voltage diodes, a gate driver IC with a fully integrated overcurrent protection function by measuring gate-to-emitter voltage ($V_{\text{GE}}$) during IGBT conduction is proposed. In the proposed gate driver IC, while the IGBTs are ON, constant gate charge is periodically discharged and charged, and when $V_{\text{GE}}$ dropped by each discharge is less than the reference voltage, it is detected as the overcurrent and the IGBTs are immediately turned off to protect from the overcurrent. In a single-pulse test of an inductive load at 300 V for an IGBT with a pulse rating of 200 A, the proposed gate driver IC fabricated with 180-nm BCD process successfully protected the overcurrent of 370 A with the protection delay of 810 ns.