Hello,
The Kelvin emitter pin connection eliminates the effect of parasitic inductance shared by the gate driver circuit and the main power circuit.
The negative impact of this common-emitter inductance is significantly increased at high switching frequency operation where mainly high di/dt’s are present, increasing the switching losses and generating risky gate voltage spikes that could cause spurious turn-on, and/or destroy the IGBT.
Details of the importance of the Kelvin emitter pin are discussed at length in this application note:
https://www.infineon.com/dgdl/Infineon-Application+Note+TRENCHSTOP%E2%84%A2+5+in+TO-247+4pin-AN-v01_...Thank you
