1N6291A — 1500W Zener TVS in DO-201AD
That 1.5 kW rating means it can absorb a substantial surge without failing — the key metric for protecting a DC rail or signal line against lightning-induced transients or inductive load dumps. Three voltages define the protection window: reverse standoff is 58.1V — this is the maximum DC voltage the diode will not conduct at. Breakdown minimum is 64.6V (the avalanche threshold). For a 48V nominal bus with transients, this diode clamps hard before the downstream silicon fails. Single unidirectional channel in a DO-201AD axial package with through-hole mounting.
onsemi lists the 1N6291A as Obsolete. The wide junction temperature range (-65°C to 175°C) and 1500W pulse rating mean this part was often used in high-reliability designs. If you are filling a legacy BOM, the obsolete status is the main risk — confirm the quantity needed and we will search our network for verified stock.
Package and mounting — DO-201AD axial
DO-201AD (also known as R-6) is a through-hole axial package — the body is about 9.1 mm long with 1.3 mm diameter leads. Hand-solder or wave-solder; the leads must be formed for through-hole PCB mounting or point-to-point wiring. No surface-mount variant exists in this series. The through-hole form factor makes it straightforward to replace in a retrofit or repair scenario — no reflow profile needed, just a soldering iron and a desoldering tool.