The 1.5SMC18A_R1_00001: This power rating defines the device's ability to clamp transients without exceeding the junction temperature limit of 150 °C.
Package, mounting, and temperature grade
This is a unidirectional device (one channel), meaning it clamps transients in one polarity only. For bidirectional protection on AC or bipolar rails, two devices or a bidirectional variant from the same series would be needed.
Active production and sourcing posture
No pin-compatible second-source or successor is recorded on this line.