Novel Short-Circuit Detection Using an Isolated Add-on Coil on a Type-B LV-nHPD2 Package

Abstract:
This paper presents a high-speed method for detecting short circuits using an isolated add-on sensing coil with a di/dt detection circuit. The results of an electromagnetic field analysis show that the magnetic flux density was highest in a diagonal-intersection area inside the laminated PN terminals, making it the most suitable for detection. The detection time was approximately 0.78 mus for the waveforms measured in a short-circuit evaluation using a prototyped sensing coil printed circuit board (PCB) and di/dt detection PCB, satisfying the target of < 1 mus. A soft shutdown operation was activated as a result of our combinatorial evaluation with the di/dt detection PCB and a test gate driver that had a short-circuit protection function.