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STMicroelectronics STD3N40K3 — Discrete Semiconductors

STD3N40K3 N-Channel MOSFET, 400 V, 2 A, SuperMESH3

MPNSTD3N40K3
Obsolete

STMicroelectronics SuperMESH3™ STD3N40K3, N-Channel MOSFET, 400 V Vdss, 2 A Id, 3.4 Ohm Rds(on) at 10 V, DPAK (TO-252) surface mount, -55 to 150 °C.

$1.5200Ref. price · indicative, final on quote
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

STD3N40K3 specifications
ParameterValue
SeriesSuperMESH3™
FET typeN-Channel
MountingSurface Mount
Drain to source voltage400 V
Drive voltage (Max rds on, min rds on)10V
Current - continuous drain (Id) @ 25°C2A (Tc)
Power dissipation30W (Tc)
Operating temperature-55°C ~ 150°C (TJ)
PackageTape & Reel (TR) Cut Tape (CT)
Vgs±30V
TechnologyMOSFET (Metal Oxide)
CaseTO-252-3, DPak (2 Leads + Tab), SC-63
Vgs(th) (Max) @ id4.5V @ 50µA
Rds on (Max) @ id, vgs3.4Ohm @ 900mA, 10V
Gate charge (Qg) (Max) @ vgs11 nC @ 10 V
Input capacitance (Ciss) (Max) @ vds165 pF @ 50 V

Product details

400 V, 2 A N-channel — SuperMESH3 in a DPAK

At 2 A the conduction loss hits about 13.6 W — well within the 30 W package dissipation limit at the case, but the junction-to-ambient thermal path in a DPAK will need a decent copper area or a heatsink to keep the junction below 150 °C.

The STD3N40K3 carries an Obsolete lifecycle status. STMicroelectronics has ended production, and no last-time-buy window remains open through the factory channel.

DPAK footprint and temperature range

The DPAK (TO-252) package has a tab that is electrically the drain.

Frequently asked questions

What is the replacement for STD3N40K3?

For a pin-compatible drop-in, look at other SuperMESH3 N-channel MOSFETs in DPAK with similar 400 V / 2 A ratings — the STD3N40K4 is a close sibling in the same series, but confirm the Rds(on) and gate charge differences against your design margin before substituting.

Is STD3N40K3 obsolete?

Yes. The lifecycle status is Obsolete — STMicroelectronics has discontinued production. No last-time-buy window is active through the factory channel.