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STMicroelectronics STD9NM50N — Discrete Semiconductors

STD9NM50N N-Channel MOSFET, 500 V, 5 A, DPAK - MDmesh II

MPNSTD9NM50N
Active

STMicroelectronics STD9NM50N, MDmesh™ II N-channel MOSFET, 500 V Vdss, 5 A continuous drain, 790 mOhm Rds(on) at 10 V, 14 nC gate charge, DPAK surface-mount package, 150°C junction temperature.

$1.4600Ref. price · indicative, final on quote
PackagingTO-252-3, DPak (2 Leads + Tab), SC-63
RoHSROHS3 Compliant
SeriesMDmesh™ II
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

STD9NM50N specifications
ParameterValue
SeriesMDmesh™ II
FET typeN-Channel
MountingSurface Mount
Drain to source voltage500 V
Drive voltage (Max rds on, min rds on)10V
Current - continuous drain (Id) @ 25°C5A (Tc)
Power dissipation45W (Tc)
Operating temperature150°C (TJ)
PackageTape & Reel (TR) Cut Tape (CT)
Vgs±25V
TechnologyMOSFET (Metal Oxide)
CaseTO-252-3, DPak (2 Leads + Tab), SC-63
Vgs(th) (Max) @ id4V @ 250µA
Rds on (Max) @ id, vgs790mOhm @ 2.5A, 10V
Gate charge (Qg) (Max) @ vgs14 nC @ 10 V
Input capacitance (Ciss) (Max) @ vds570 pF @ 50 V

Product details

The 500 V rating places it squarely in offline flyback converters, auxiliary power supplies, and 2-switch forward topologies where the primary-side MOSFET sees the rectified mains plus reflected voltage — typically 400 V to 500 V peak on a 230 VAC input with a 1.3× derating margin. At 2.5 A continuous, expect I²R loss of about 4.9 W — well within the 45 W power dissipation capability of the DPAK package when the PCB copper area under the tab is sized correctly.

A typical gate driver sourcing 1 A peak can switch this MOSFET in about 14 ns — fast enough for 100 kHz hard-switching without excessive Miller plateau dwell. The low Qg also means a simple bootstrap supply on the high-side driver is sufficient; no external charge pump or isolated bias rail required. Input capacitance Ciss is 570 pF at 50 V drain bias. Combined with the 14 nC Qg, the switching energy per cycle is modest — the MOSFET is a good fit for medium-frequency converters where the driver IC is a standard 1 A to 2 A part rather than a specialised high-current module.

For volume production commitments, the active lifecycle means no forced redesign cycle from a looming EOL.

Frequently asked questions

What is the replacement for STD9NM50N?

The part is active, so no replacement is required. For a pin-compatible alternative, the STD9NM60N (600 V variant) shares the same DPAK footprint and gate drive voltage, but the 100 V higher drain rating comes with a different Rds(on) and gate charge — confirm the electrical margin before substituting.

Is STD9NM50N RoHS compliant?

Yes, the STD9NM50N is ROHS3 compliant, covering the current EU RoHS exemption landscape.