ESD Tolerance Improvement of Power Module using Clamp Diodes Built into Control IC

Higher tolerance to electrostatic discharge (ESD) is desired for protection of equipment for HVAC in electrified transportation applications such as an EV bus. In recent years, Intelligent Power Modules (IPMs) that integrate power chips and ICs are generally applied as components in these HVAC inverters. These power modules control large current and high voltage and are implicitly recognized to have high ESD tolerance. However, in an emitter-sense method, which is one of overcurrent detection methods, power chips with emitter-sense are weak against ESD even though the emitter-sense is a part of the power chip. As a general protection method, it is conceivable to attach an RC filter or protection diode externally to increase the tolerance capacity, but there is a disadvantage that the entire system becomes larger. This paper introduces an ESD tolerance improvement without changing the size of the IPM housing and the operation of the circuit by integrating a protection circuit consisting of clamp diodes in the IC.