Ogu Reginald
Full Member level 6
What does it mean if a triac is said to be snubberless in its datasheet?
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A component specified by its datasheet as Snubberless, simply indicates that the component does not incorporate a Snubber circuit. And depending on the circuit design an additional appropriate Snubber Cricuit will need to be included.
BigDog
Actually, Snubberless Triacs typically don't require a snubber circuit because of their enhanced commutation performance.
IS IT ALWAYS POSSIBLE TO REMOVE THE
SNUBBER CIRCUIT ?
The answer is not in the affirmative because
sometimes it has other functions :
improvement of the triac immunity against transients
in the off state ;
compensation of latching current at turn on (not
dealt in this paper).
Switching on and voltage perturbations can
provoke overvoltages and fast voltage variations
across the triac :
this one could break over when the overvoltages
are higher than its repetitive peak off state voltage,
VDRM;
due to the junction capacitance fast voltage variations
create a gate current and could trigger the
triac; the device limit is the rate of rise of the offstate
voltage, dV/dt.
The snubber circuit can improve the triac behavior
in off-state. But its efficiency is linked to the values
of series inductance L at the oscillation frequency
of perturbations (typically higher than 100 kHz).
We could add a saturable inductor in series with
the triac when L is too low: particularly this is the
case of resistive load.