Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

Home > Products > Discrete Semiconductor Products > Transistors > FETs, MOSFETs > FETs, MOSFETs

STMicroelectronics STP21NM50N

Name: STP21NM50N
Brand: STMicroelectronics
SKU: STP21NM50N
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: STP21NM50N

Manufacturer:: STMicroelectronics

Category:: FETs, MOSFETs

Package:: TO-220-3

Datasheet:: STP21NM50N.pdf

Description:: MOSFET N-CH 500V 18A TO220AB

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:5,869

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

STP21NM50N from STMicroelectronics is an N-channel 500 V, 0.15 Ω (typ), 18 A TO-220 Power MOSFET based on second-generation MDmesh™ technology. It delivers low gate charge (65 nC), low input capacitance (1950 pF), and 100% avalanche-tested ruggedness for high-efficiency hard-switched SMPS in industrial AC-DC and DC-DC converters.

For engineers reviewing the STP21NM50N datasheet, STP21NM50N pinout, STP21NM50N application, or STP21NM50N equivalent, key selection criteria include R_DS(on) at 10 V drive, unclamped inductive switching capability (E_AS = 480 mJ), thermal resistance (R_thj-case = 0.89 °C/W), and TO-220 package compatibility with standard heatsink mounting.

Technical Context

This MOSFET employs ST's proprietary strip-based vertical MDmesh™ structure to minimize conduction and switching losses simultaneously. Its 500 V V_DSS rating with 550 V surge capability supports operation across universal mains (85–265 V_AC) with margin, while the 0.15 Ω typical R_DS(on) enables high-current primary-side switching without forced air cooling.

The device features a fast body diode (t_rr = 360 ns at T_j = 25°C) and low Q_gd/Q_g ratio (30/65 nC), supporting ZVS-capable topologies like LLC resonant converters. Gate threshold voltage (2–4 V) ensures robust noise immunity and compatibility with standard 10 V gate drivers.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DSS	500 V - Withstands 550 V transient surges; suitable for 400 V DC bus designs with safety margin.
R_DS(on) (typ)	0.15 Ω @ V_GS = 10 V, I_D = 9 A - Enables <1.2 W conduction loss at 18 A, reducing heatsink requirements.
Q_g	65 nC - Low total gate charge minimizes driver power loss and enables >100 kHz switching in PFC stages.
E_AS	480 mJ - Confirmed single-pulse avalanche energy allows reliable operation under inductive fault conditions.
R_thj-case	0.89 °C/W - Enables 140 W dissipation at T_C = 25°C; supports compact heatsink integration in enclosed power supplies.
t_rr	360 ns @ I_SD = 18 A, di/dt = 100 A/µs - Fast body diode recovery reduces switching loss and EMI in flyback and forward converters.

Pinout & Package

STP21NM50N uses a standard TO-220 package with three leads: Gate (pin 1), Drain (pin 2), Source (pin 3). The drain-connected tab is electrically tied to pin 2 and serves as the primary thermal path to the heatsink.

Pin/Terminal	Circuit Role	Design Meaning
1 (Gate)	Control terminal	Receives 10 V logic-level drive; 1.6 Ω gate input resistance simplifies RC snubber design.
2 (Drain)	High-side power output	Connected to drain metallization and heatsink tab; must be isolated from chassis unless referenced to ground.
3 (Source)	Power return / reference node	Serves as local ground reference for gate drive; low-inductance PCB layout critical for dV/dt immunity.

Key Features

Feature	Design Value
Second-generation MDmesh™ structure	Reduces R_DS(on) × Q_g figure-of-merit by >30% vs. first-gen, enabling higher efficiency at 100–300 kHz.
100% avalanche tested	Guarantees E_AS ≥ 480 mJ per unit-no derating needed for unclamped inductive turn-off in PFC boost stages.
Low C_iss/C_oss ratio	1950 pF / 420 pF enables predictable Miller plateau timing and stable gate drive in high-dV/dt environments.
ECOPACK® lead-free package	Meets RoHS and JEDEC JESD97 standards; compatible with standard SnPb and Pb-free reflow profiles.

Applications

Industrial AC-DC Power Supplies

Server & Telecom Rectifiers

Use Scenario: Primary-side switch in 500–1000 W active clamp forward or half-bridge converters operating from 3-phase 400 V AC input.

IC Role / Device Role / Timing Role: High-voltage, high-current main power switch handling full load current during each switching cycle.

Use Value: 0.15 Ω R_DS(on) limits conduction loss to <4.9 W at 18 A, enabling natural convection cooling in space-constrained rack-mount units.

Use Scenario: Boost PFC stage in 80+ Platinum-certified 1.5 kW telecom rectifier with 94% peak efficiency target.

IC Role / Device Role / Timing Role: Critical conduction mode (CrM) or continuous conduction mode (CCM) switch managing 12 A RMS input current.

Use Value: 65 nC Q_g and 360 ns t_rr reduce switching loss by 18% vs. legacy 500 V MOSFETs, directly contributing to efficiency compliance.

Motor Drive Inverters

Renewable Energy Converters

Use Scenario: Phase-leg switch in 3 kW HVAC inverter driving permanent magnet synchronous motors at 16 kHz PWM frequency.

IC Role / Device Role / Timing Role: Half-bridge upper/lower switch subjected to repetitive dv/dt stress up to 15 V/ns during commutation.

Use Value: 15 V/ns dv/dt rating and 100% avalanche testing ensure robustness against shoot-through-induced overvoltage transients.

Use Scenario: DC-DC isolation stage in 3 kW solar microinverter interfacing 600 V PV string to 400 V battery bank.

IC Role / Device Role / Timing Role: High-side switch in dual-active-bridge topology requiring precise zero-voltage switching control.

Use Value: Low Q_gd/Q_g ratio (46%) improves ZVS soft-switching window, reducing transformer core loss and EMI filter size.

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage power switching applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
IPP60R190C6	650 V, 0.19 Ω, 18 A, TO-220; CoolMOS™ C6 with lower Q_g (42 nC) but higher R_DS(on).	Better suited for >200 kHz resonant topologies where gate drive loss dominates; less optimal for hard-switched PFC.	Select when prioritizing ultra-low switching loss over conduction loss in high-frequency ZVS designs.
IRFP460	500 V, 0.27 Ω, 20 A, TO-247; legacy planar MOSFET with higher R_DS(on), no avalanche rating, and 3× higher Q_g.	Limited to <50 kHz hard-switched applications; requires larger heatsink and gate driver due to 120 nC Q_g.	Consider only for legacy redesigns where footprint compatibility with TO-247 is mandatory and efficiency targets are relaxed.

Compared with IPP60R190C6 and IRFP460, STP21NM50N offers the best balance of low R_DS(on), moderate Q_g, and guaranteed avalanche ruggedness-making it ideal for cost-sensitive, thermally constrained 50–150 kHz industrial SMPS where reliability under overload is critical.

Availability

STP21NM50N is available at Aetrix Electronics and suitable for industrial AC-DC power supplies, server rectifiers, and motor drive inverters requiring stable component supply and long-term production continuity.

Supply support for STP21NM50N includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in power, analog, MEMS, and microcontroller technologies for industrial, automotive, and consumer markets.

STP21NM50N belongs to the MDmesh™ high-voltage Power MOSFET product line, engineered specifically for high-efficiency, high-reliability switched-mode power conversion in industrial and telecom infrastructure.

FAQ

What is the maximum continuous drain current for STP21NM50N at 100°C case temperature?

The maximum continuous drain current is 11 A at T_C = 100°C, as specified in Table 1 of the datasheet. This derating reflects thermal limitations of the TO-220 package, not silicon capability-actual current handling depends on heatsink performance and ambient conditions.

Does STP21NM50N require a negative gate voltage for reliable turn-off?

No. STP21NM50N has a gate threshold voltage range of 2–4 V and is fully enhanced at V_GS = 10 V. A gate drive of 0 V is sufficient for turn-off; applying –5 V is unnecessary and not recommended per ST's application guidance.

Can STP21NM50N replace STW21NM50N in a TO-247 footprint design?

No. STP21NM50N uses TO-220 packaging with different pin spacing, thermal pad geometry, and mounting hole locations than TO-247. Mechanical incompatibility prevents direct replacement without PCB redesign and thermal reassessment.

Is STP21NM50N qualified for automotive applications?

No. STP21NM50N is not automotive-grade (AEC-Q101 qualified) and is intended for industrial, telecom, and consumer power systems. ST does not recommend or warrant its use in automotive safety-critical or engine-bay environments.

STP21NM50N Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: MDmesh™ II

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 500 V

Current - Continuous Drain (Id) @ 25°C:: 18A (Tc)

Drive Voltage (Max Rds On, Min Rds On):: 10V

Rds On (Max) @ Id, Vgs:: 190mOhm @ 9A, 10V

Vgs(th) (Max) @ Id:: 4V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 65 nC @ 10 V

Vgs (Max):: ±25V

Input Capacitance (Ciss) (Max) @ Vds:: 1950 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 140W (Tc)

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

STP21NM50N FAQ

1.How can I place an order for STP21NM50N through Aetrix?

Please submit a Request for Quotation (RFQ) for STP21NM50N on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for STP21NM50N reliable?

The price and inventory of STP21NM50N are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STP21NM50N is usually 5 days.

3.What payment methods are accepted for STP21NM50N?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STP21NM50N transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STP21NM50N?

STP21NM50N orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STP21NM50N order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for STP21NM50N?

For technical support, including STP21NM50N datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STP21NM50N requirements.

6.How does Aetrix verify that STP21NM50N is sourced from the original manufacturer or authorized distributors?

All STP21NM50N products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that STP21NM50N meets industry standards.

7.What is the process for return or replacement of STP21NM50N?

All STP21NM50N units undergo pre-shipment inspection (PSI). If there is an issue with STP21NM50N, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The STP21NM50N part is unused and in its original packaging.

Return procedure for STP21NM50N:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

Tech Hub

2026-09-03 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-01 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…

2026-08-18 Operational Amplifier (Op Amp): Basics, Configurations, Feedback and Applications

Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…

2026-08-14 Jumper Cables: How to Use, Connect and Choose Them Safely

Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…