BTA420 3-Quadrant High-Commutation Triacs WeEn Semiconductors BTA420 3-Quadrant High-Commutation Triacs are planar passivated, high commutation three-quadrant triacs intended for use in circuits where high static and dynamic dV/dt and high dI/dt can occur. The WeEn Semiconductors BTA420 series triacs will commutate the full RMS current at the maximum rated junction temperature (Tj(max) = 150°C) without the aid of a snubber. It is used in applications that require high junction operating temperature capability.