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STMicroelectronics STB21N65M5

STB21N65M5 MDmesh V N-Ch MOSFET, 650V 17A D2PAK

MPNSTB21N65M5
End of Life

STMicroelectronics MDmesh V series N-channel MOSFET, STB21N65M5, 650 Vdss, 17 A continuous drain, 190 mOhm Rds(on) at 10 V, D2PAK (TO-263) surface-mount package.

$5.06Ref. price · indicative, final on quote
PackagingTO-263-3, D²Pak (2 Leads + Tab), TO-263AB
RoHSROHS3 Compliant
SeriesMDmesh™ V
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

STB21N65M5 specifications
ParameterValue
SeriesMDmesh™ V
FET typeN-Channel
MountingSurface Mount
Drain to source voltage650 V
Drive voltage (Max rds on, min rds on)10V
Current - continuous drain (Id) @ 25°C17A (Tc)
Power dissipation125W (Tc)
Operating temperature150°C (TJ)
PackageTape & Reel (TR); Cut Tape (CT)
Vgs±25V
TechnologyMOSFET (Metal Oxide)
CaseTO-263-3, D²Pak (2 Leads + Tab), TO-263AB
Vgs(th) (Max) @ id5V @ 250µA
Rds on (Max) @ id, vgs190mOhm @ 8.5A, 10V
Gate charge (Qg) (Max) @ vgs50 nC @ 10 V
Input capacitance (Ciss) (Max) @ vds1950 pF @ 100 V

Product details

650 V, 190 mOhm — what that buys in an offline supply

That voltage class targets the primary side of offline flyback, PFC boost, and LLC resonant converters where the DC bus sits around 400 V and the drain rings past 600 V during turn-off.

For a 100 kHz hard-switched converter, the gate-drive power is Qg × Vgs × fsw = 50 nC × 10 V × 100 kHz = 50 mW — well within a standard driver's dissipation. Keep the gate-loop inductance tight; a 10 Ω series gate resistor is a typical starting point to damp ringing without slowing the edge too much.

Thermal and mounting — D2PAK real estate

Maximum power dissipation is 125 W at case temperature. A two-layer board with a 2 oz copper pad under the tab and vias to an internal plane keeps the junction below 125°C at 30–40 W dissipation. Surface-mount assembly: standard reflow profile for lead-free solder. The tab solder joint is visually inspectable from the board edge. No special moisture sensitivity level is stated, but a bake at 125°C for 24 hours before reflow is safe practice if the tape has been opened and exposed to humid shop air.

Frequently asked questions

What is the Rds(on) of STB21N65M5?

Maximum on-resistance is 190 mOhm at 8.5 A drain current with 10 V gate drive.

Is STB21N65M5 RoHS compliant?

Yes, it is listed as ROHS3 compliant.