Repeated Driver Module Failures on 2SC0435T2F1-17 During Arc Events (VISO Burnout, IGBT Short)

Hello,

We are using two 2SC0435T2F1-17 driver modules to run four FZ600R17KE4 IGBTs in parallel, with each driver channel controlling a single IGBT. These IGBTs are connected to the primary side of the transformer.

The system is designed to withstand arc events on the secondary side of the transformer, with additional protection circuits implemented to shut it down when such events occur. Active clamping has been configured per the manual, but desaturation detection was removed since it proved too slow for this application.

However, after 3–5 arc events, we consistently see failures in one of the driver ICs, specifically at the VISOx pin, which shows clear burn damage (see attached photo-Marked in Red). At the same time, the diode between GHx and COMx is shorted (failed diode is marked in blue). In each case, the corresponding IGBT also fails, with G–E and C–E both shorted. The failure mode appears to be: driver module failure → IGBT failure.

I posted the same issue while ago here https://www.power.com/community/forum/gate-drivers-forum/2025/2sc0435t2f1-17-failure-power-root-cause-suggestions and the support team suggested over currenting VISO is the issue. The baseboard setup has been verified against the manual (without desaturation protection). Blocking capacitors (C1x and C2x) are 9.7 µF, sized according to the IGBT gate charge.

We also observed that during arc events the gate–emitter voltage spikes above the ±20 V rating of the IGBT. Based on discussions here: https://www.power.com/community/forum/gate-drivers-forum/2024/2sc0435t-and-gate-to-collector-igbt-shortcircuit that discusses a failure mode similar to ours we implemented two Zener diodes (18V) in opposite polarity across the gate emitter with a 10k resistor parallel parallel to them. It was also tested with TVS diodes. Unfortunately, neither solution prevented failure—modules and IGBTs continue to fail after 3–4 arc events.

Could you provide guidance on:

• Possible root causes of VISO pin burnout under arc conditions.
• Recommended circuit modifications or additional protections to prevent repeated driver/IGBT failures.

Any insights or recommendations on preventing these failures would be greatly appreciated. I’m also happy to provide additional information such as scope captures or schematics if needed.