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STMicroelectronics STF12NM50ND — Discrete Semiconductors

STF12NM50ND N-Channel MOSFET, 500 V, 11 A, FDmesh II

MPNSTF12NM50ND
Obsolete

STMicroelectronics FDmesh™ II series, STF12NM50ND, N-Channel MOSFET, 500 Vdss, 11 A Id, 380 mOhm Rds(on), 30 nC Qg, TO-220-3 Full Pack, Through Hole, 150°C junction.

$2.1000Ref. price · indicative, final on quote
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

STF12NM50ND specifications
ParameterValue
SeriesFDmesh™ II
FET typeN-Channel
MountingThrough Hole
Drain to source voltage500 V
Drive voltage (Max rds on, min rds on)10V
Current - continuous drain (Id) @ 25°C11A (Tc)
Power dissipation25W (Tc)
Operating temperature150°C(TJ)
PackageTube
Vgs±25V
TechnologyMOSFET (Metal Oxide)
CaseTO-220-3 Full Pack
Vgs(th) (Max) @ id5V @ 250µA
Rds on (Max) @ id, vgs380mOhm @ 5.5A, 10V
Gate charge (Qg) (Max) @ vgs30 nC @ 10 V
Input capacitance (Ciss) (Max) @ vds850 pF @ 50 V

Product details

500 V, 11 A N-channel in a fully isolated TO-220FP

This simplifies assembly and reduces thermal interface resistance in offline power supplies and flyback converters where the heatsink may be at chassis potential.

These figures place the STF12NM50ND in a moderate-speed class — suitable for hard-switched topologies in the 50–150 kHz range where the gate-drive current requirement stays under 150 mA. Maximum power dissipation is 25 W at case temperature, with the junction rated to 150 °C. In a typical flyback converter dissipating 10–15 W, the TO-220FP's junction-to-case thermal path through the full-pack moulding runs about 5–6 °C/W — budget a heatsink with adequate surface area to keep the junction below 125 °C for reliable operation.

STMicroelectronics lists the STF12NM50ND as obsolete. For new designs, evaluate the STF12NM50N (non-isolated TO-220) or a current FDmesh™ II or MDmesh™ series part with similar 500 V / 11 A ratings; the TO-220FP footprint is specific to the full-pack variant. Availability is limited to surplus and broker-channel inventory.

Frequently asked questions

Is the STF12NM50ND obsolete?

Yes, STMicroelectronics has marked the STF12NM50ND as obsolete. There is no official successor part listed. For replacement, consider a current FDmesh™ II or MDmesh™ series MOSFET with similar 500 V / 11 A ratings in a TO-220FP or standard TO-220 package, depending on the isolation requirement.

What is the difference between STF12NM50ND and STF12NM50N?

The STF12NM50ND is the fully isolated TO-220 Full Pack variant; the STF12NM50N is the standard TO-220 with a non-isolated metal tab. The electrical ratings (500 V, 11 A, 380 mOhm) are the same, but the ND version does not require an insulating washer between the device and the heatsink.