Transient suppressor for 18 V rails
The 1N6151A is a bidirectional Zener TVS diode from Microchip Technology designed to clamp voltage transients on 18.2 V nominal rails. With a peak pulse power rating of 1500 W and a clamping voltage of 33.3 V at 45 A, it protects downstream silicon from surges without needing a series fuse or additional steering diodes.
Voltage window and surge current
Breakdown occurs at 22.8 V minimum, ensuring the diode remains off below the rail tolerance. The 33.3 V clamp ceiling limits the voltage the protected load sees during a 45 A pulse — a critical number for selecting downstream capacitor voltage ratings and MOSFET Vds margins. The bidirectional structure means polarity-insensitive installation: either lead can connect to the rail or ground, which simplifies PCB layout for AC-coupled or floating supplies.
Thermal range and package realities
The B Axial through-hole package requires a drilled hole and solder wave — not a reflow footprint — so factor in manual assembly or selective solder for prototype runs.
Production status and sourcing posture
Listed as Active with no announced EOL or NRND notice. Microchip continues to manufacture the 1N6151A in the B Axial package. Sourced per RFQ against BOM quantity; no stock-holding claim on this page.