500W bidirectional Zener clamp – DO-15 axial
The SA15CA: It clamps transients at 24.4V max, handling 20.6A peak pulse current. The single bidirectional channel means it protects both positive and negative surges — useful on AC signal lines or bipolar DC rails where polarity isn't fixed.
onsemi lists the SA15CA as Obsolete. A board-level replacement would require a different order code; no pin-compatible drop-in is documented.
Through-hole mounting – DO-15 axial footprint
The SA15CA ships in a DO-204AC (DO-15) axial-lead package. Through-hole mounting means it survives reflow without MSL concerns — the leads solder into plated through-holes, and the body stands off the board.