SMC TVS in DO-214AB
The 1.5SMCJ9.0CA is a unidirectional Zener-type TVS diode in the DO-214AB (SMC) surface-mount package. The SMC footprint demands a well-designed copper pad on the PCB — at 1.5 kW peak pulse the diode junction self-heats during a surge event, and the board pad is the primary heatsink path.
Standoff, clamping, and peak pulse current
9 V reverse standoff (typ) is the working voltage the protected line sits at during normal operation. That 15.4 V is the number that protects downstream circuits. Bidirectional, single-channel — it clamps both polarities of surge event on a single line, which is the typical configuration for power and data lines in equipment without a defined ground reference polarity.