Type SCM Single/Dual IGBT Snubber Capacitor Modules

High Peak Current Snubber with Integrated Hyperfast Diode

Typical Applications

Discharge Restrictive De-coupling

The circuit in Figure 1 operates on the same principles as the

de-coupling capacitor, but only during turn-of switching. As

the IGBT turns of, energy trapped in the loop inductance is

transferred to the capacitor. The diode blocks oscillations from

occurring and excess charge on the capacitor is discharged

through the external resistor.

• 1 or 2 wire taps for connecting external resistor

• Flame resistant case and epoxy, meets UL 94V0

• Other terminal pitches and capacitance values

available.

Figure 1

Style SCM Discharge restrictive decoupling used

to protect dual IGBT modules

RCD Clamp

The function of this snubber is similar to a clamp, Figure 2. At

turn-of, the snubber diode is forward biased and the snubber

is activated. The energy trapped in the stray inductance is

absorbed by the snubber capacitor. During turn-on the snubber

caps that were fully charged to bus voltage have a discharge

path through the forward biased free-wheel diode, the IGBT,

and the snubber resistors. This reduces the reverse recovery

voltage transient.

Figure 2

Style SCM “P” type and “N” type used as a clamp to protect

an inverter using two “single” IGBT modules

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