Skip to main content
Log in
STMicroelectronics STFW1N105K3 — Discrete Semiconductors

STFW1N105K3 N-Channel MOSFET, 1050 V, 1.4 A, TO-3PF

MPNSTFW1N105K3
NRND

STMicroelectronics SuperMESH3™ N-Channel MOSFET, 1050 V Vdss, 1.4 A Id, 11 Ohm Rds(on) @ 600 mA, 10 V, TO-3P-3 Full Pack, Through Hole, -55°C to 150°C.

$2.4421Ref. price · indicative, final on quote
STMicroelectronics STFW1N105K3 datasheet (PDF)
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

STFW1N105K3 specifications
ParameterValue
SeriesSuperMESH3™
FET typeN-Channel
MountingThrough Hole
Drain to source voltage1050 V
Drive voltage (Max rds on, min rds on)10V
Current - continuous drain (Id) @ 25°C1.4A (Tc)
Power dissipation20W (Tc)
Operating temperature-55°C ~ 150°C (TJ)
PackageTube
Vgs±30V
TechnologyMOSFET (Metal Oxide)
CaseTO-3P-3 Full Pack
Vgs(th) (Max) @ id4.5V @ 50µA
Rds on (Max) @ id, vgs11Ohm @ 600mA, 10V
Gate charge (Qg) (Max) @ vgs13 nC @ 10 V
Input capacitance (Ciss) (Max) @ vds180 pF @ 100 V

Product details

High-voltage N-channel MOSFET for power conversion

The STFW1N105K3: The 11 Ohm maximum on-resistance at 600 mA gate drive of 10 V keeps conduction losses manageable in high-voltage off-line power supplies, LED lighting drivers, and auxiliary converters where the primary-side switch sees rectified mains.

Key ratings for the BOM decision

The 1050 V Vdss rating provides margin above rectified mains rails and covers universal-input flyback converters with reflected voltage. The 1.4 A continuous current is sized for auxiliary windings and lower-power stages; the 20 W power dissipation ceiling at case temperature sets the thermal budget for the heatsink design. Gate charge of 13 nC at 10 V is modest, keeping driver losses low in switching frequencies up to 100 kHz. The ±30 V maximum gate-source voltage gives good noise immunity on the gate drive, but the recommended drive voltage for rated Rds(on) is 10 V.

Frequently asked questions

Is STFW1N105K3 obsolete or still available?

It is not yet discontinued but is on the path to end of life; it remains available for existing production runs but is not recommended for new designs. Buyers should plan for a last-time buy or a replacement qualification.

What is the replacement for STFW1N105K3?

A replacement will need to be selected from the SuperMESH3 family or a competitive high-voltage N-channel MOSFET with similar Vdss, current rating, and package (TO-3PF). Key parameters to match include the 1050 V Vdss, 1.4 A Id, 11 Ohm Rds(on), and gate charge characteristics.