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STMicroelectronics STP21NM50N — Discrete Semiconductors

STP21NM50N N-Channel MOSFET, 500V, 190mOhm, MDmesh II

MPNSTP21NM50N
Obsolete

STMicroelectronics STP21NM50N, MDmesh™ II Series, N-Channel MOSFET, 500 V drain-source, 18 A continuous drain, 190 mOhm Rds(on) at 9 A and 10 V, TO-220-3 through-hole package, 150 °C junction temperature.

$5.6800Ref. price · indicative, final on quote
STMicroelectronics STP21NM50N datasheet (PDF)
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

STP21NM50N specifications
ParameterValue
SeriesMDmesh™ 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°C18A (Tc)
Power dissipation140W (Tc)
Operating temperature150°C (TJ)
PackageTube
Vgs±25V
TechnologyMOSFET (Metal Oxide)
CaseTO-220-3
Vgs(th) (Max) @ id4V @ 250µA
Rds on (Max) @ id, vgs190mOhm @ 9A, 10V
Gate charge (Qg) (Max) @ vgs65 nC @ 10 V
Input capacitance (Ciss) (Max) @ vds1950 pF @ 25 V

Product details

Any BOM line using this part needs a validated replacement or a bridge buy from spot inventory.

500 V, 190 mOhm, 18 A — the power-switching envelope

This is a 500 V N-channel MOSFET from ST's MDmesh™ II family, built for high-voltage switched-mode power supplies, power-factor-correction stages, and motor-drive inverters. Gate charge is 65 nC at 10 V, a figure that sets the drive power in a high-frequency converter.

TO-220 package — through-hole mounting and thermal interface

The junction-to-case thermal path is the main dissipation route — the 140 W power rating assumes a good thermal interface to a heatsink. No exposed pad or surface-mount option exists; board assembly is manual or wave-solder.

Frequently asked questions

What is the replacement for STP21NM50N?

No official replacement part number is recorded in the lifecycle data. A same-function 500 V N-channel MOSFET from ST's current MDmesh series (e.g., MDmesh V or MDmesh K5 families) should be evaluated for pin-compatibility and parametric fit. The TO-220 footprint is standard, but gate charge, Rds(on), and switching performance will differ.

What is the Rds(on) of STP21NM50N?

The maximum Rds(on) is 190 mOhm at a drain current of 9 A and a gate-source voltage of 10 V.