IRF840PBF

IRF840PBF is a Vishay N-channel power MOSFET in a TO-220AB package, rated at 500 V drain-source voltage and 8 A continuous drain current, with maximum on-resistance of 0.85 Ω and total gate charge of 63 nC — a long-established high-voltage switch for offline power supplies, UPS stages, motor drives and legacy industrial equipment. On lifecycle, Vishay's own product-termination documentation confirms this code as a continuing alternate: it has never appeared on Vishay's Obsolete list, and the orderable code to quote is IRF840PBF. Selection advice: the 63 nC gate charge is the practical design figure — at high switching frequency the gate driver must supply it, so check driver peak current before assuming a logic-level drive will hold the switching edges this part can deliver. Modern superjunction MOSFETs beat its on-resistance on paper, but in a qualified legacy design this code's value is exact continuity: same package, same documented characteristics, no requalification. Require lot and date-code traceability for this classic part number, since re-marked stock circulates under the IRF840 name. Parameters verified against Vishay documentation.