The 1.5KE18A-HF: For a 12 V nominal supply with transients, the 15.3 V standoff provides margin above the regulated output. Breakdown occurs at a minimum of 17.1 V, and the clamping voltage is 25.2 V at the full 59.52 A peak pulse current. The clamp voltage is what appears across the protected load during a surge; the 25.2 V ceiling must stay below the downstream component's absolute maximum rating.
Package, mounting, and temperature range
Housed in a DO-201AA (DO-27) axial leaded package, the 1.5KE18A-HF is a through-hole part that mounts into a standard 0.036-inch diameter hole on the PCB. The axial body is easy to hand-solder or wave-solder, and the polarity band identifies the cathode for unidirectional orientation. The wide range means derating is minimal across typical ambient conditions.