This guide provides a short questionnaire to determine the most suitable snubber capacitor for high‑power IGBT modules. It asks about the IGBT current rating, mounting type (screw or pin) and whether the capacitor will be used alone or with a diode, then gives a starting point for voltage and capacitance selection.
The document lists the available KEMET snubber capacitor series (C4AS, C4AT, C4BS, C4BT) with their rated voltages, capacitance ranges and key characteristics such as climatic category, pulse rise time, pitch and terminal options. Series C4AS and C4AT are intended for PCB mounting, while C4BS and C4BT are for direct IGBT mounting.
| Rated Voltage | 850 VDC / 500 VAC |
|---|---|
| Capacitance Range | 0.15 – 5.0 µF |
| Climatic Category (IEC 60068‑1) | 40/85/56 |
| Pulse Rise Time (dv/dt) | 469 – 3360 V/µs |
| Pitch (lead spacing) | 27.5, 37.5, 52.5 mm |
| Terminal Type | Tinned copper, 2 or 4 wires |
The guide recommends 0.25 µF per 100 A for the C4AS series.
Series C4AS and C4AT are designed for PCB mounting.
Series C4BS and C4BT are intended for direct IGBT mounting.