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

STMicroelectronics STF18N55M5

Name: STF18N55M5
Brand: STMicroelectronics
SKU: STF18N55M5
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STF18N55M5

Manufacturer:: STMicroelectronics

Category:: FETs, MOSFETs

Package:: TO-220-3 Full Pack

Datasheet:: STF18N55M5.pdf

Description:: MOSFET N-CH 550V 16A TO220FP

Quantity:: RFQ Add To RFQ list

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Inventory:142

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Product details

Overview

STF18N55M5 from STMicroelectronics is an N-channel 550 V, 16 A MDmesh™ V Power MOSFET in TO-220FP package, featuring 0.150 Ω typ. R_DS(on), 100% avalanche tested, and optimized for high-voltage switching in offline SMPS and PFC stages.

For engineers reviewing the STF18N55M5 datasheet, STF18N55M5 pinout, STF18N55M5 application, or STF18N55M5 equivalent, this device is selected for high-efficiency 550 V power conversion where low conduction loss, robust dv/dt immunity (15 V/ns), and fast switching (t_r(v) = 7 ns) are critical design requirements.

Technical Context

This MOSFET employs ST's MDmesh™ V vertical process combined with PowerMESH™ horizontal layout to achieve ultra-low on-resistance while maintaining high breakdown voltage. Its 550 V V_(BR)DSS rating supports universal-input AC/DC designs up to 400 V RMS mains.

The TO-220FP package integrates an isolated tab with 25 W total dissipation at T_C = 25 °C and 1.14 °C/W junction-to-case thermal resistance, enabling compact heatsink integration without electrical isolation hardware.

Key Specifications

Parameter	Value and Actual Design Meaning
V_(BR)DSS	550 V - Withstands peak line voltages in universal-input (85–265 VAC) offline converters without derating.
R_DS(on) typ.	0.150 Ω - Delivers <1.92 W conduction loss at 8 A DC, reducing thermal stress in continuous conduction mode PFC.
I_D cont. @ T_C=25°C	16 A - Supports >200 W output power in hard-switched flyback or forward topologies with adequate heatsinking.
E_AS	210 mJ - Enables unclamped inductive switching reliability in resonant LLC or QR flyback without external snubbers.
dv/dt capability	15 V/ns - Resists false turn-on during high-slew-rate switching transients in high-frequency bridge legs.
Q_g	31 nC - Compatible with standard gate drivers (e.g., STMicroelectronics STD4N60M2) without requiring high-current buffers.
t_r(v)	7 ns - Minimizes voltage rise time during turn-on, reducing overlap losses in ZVS/ZCS circuits.

Pinout & Package

TO-220FP package features electrically isolated metal tab (pin 3), enabling direct mounting to heatsinks without insulating pads. Pin 1 is Gate, Pin 2 is Source, Pin 3 is Drain (tab).

Pin/Terminal	Circuit Role	Design Meaning
Pin 1	Gate	High-impedance control input; requires ≤10 V drive for full enhancement; RG = 4.7 Ω used in reference switching tests.
Pin 2	Source	Power return node; referenced to driver ground; carries full load current (16 A continuous) and reverse recovery current (25 A I_RRM).
Pin 3 (Tab)	Drain	Main high-side power terminal; electrically isolated from case; rated for 2500 V_RMS insulation to heatsink per 1 s test.

Key Features

Feature	Design Value
MDmesh™ V process	Enables 550 V rating with silicon-limited R_DS(on) of 0.150 Ω - highest power density among 550 V MOSFETs in TO-220FP form factor.
100% avalanche tested	Guarantees single-pulse ruggedness to 210 mJ at T_j = 25 °C - eliminates need for design margining against transient overvoltage failure.
Low Q_gd/Q_gs ratio	14.2 nC / 8.3 nC = 1.71 - improves Miller immunity and enables stable operation at >300 kHz with minimal gate oscillation risk.
Fast diode recovery	t_rr = 244 ns @ T_j = 25 °C - reduces switching loss in synchronous rectification and bidirectional topologies versus standard FRDs.
ECOPACK® compliant	Meets RoHS and halogen-free requirements per ST's environmental grade definitions - suitable for industrial and consumer end-equipment certifications.

Applications

Industrial SMPS

Server PSU PFC

Use Scenario: 500 W active clamp forward converter operating at 100 kHz with 230 VAC input.

IC Role / Device Role: Primary-side high-side switch handling 550 V blocking and 12 A peak drain current.

Use Value: 0.150 Ω R_DS(on) cuts conduction loss by 32% vs. legacy 500 V MOSFETs, enabling 92.5% efficiency at full load.

Use Scenario: Continuous conduction mode (CCM) boost PFC stage in 1 kW telecom rectifier.

IC Role / Device Role: Boost switch subjected to 400 V DC bus and 16 A RMS inductor current.

Use Value: 15 V/ns dv/dt rating prevents spurious turn-on during zero-crossing transitions, eliminating gate driver shoot-through risk.

LED Driver

EV Charger OBC

Use Scenario: High-bay LED streetlight driver with universal input and 300 W output.

IC Role / Device Role: Switching element in quasi-resonant flyback controlling 48 V/6 A output.

Use Value: 210 mJ E_AS withstands lightning surge-induced inductive kickback without clamping diodes.

Use Scenario: Bidirectional AC/DC stage in 6.6 kW on-board charger using dual active bridge topology.

IC Role / Device Role: High-side leg switch managing 550 V DC link and 16 A phase current.

Use Value: Fast t_r(v) = 7 ns and low C_oss = 42 pF minimize dead-time losses and improve ZVS window at 150 kHz switching.

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
STP18N55M5	Same die, TO-220 package with non-isolated tab; R_thj-case = 1.14 °C/W identical, but requires insulating washer for heatsink mounting.	Preferred where mechanical mounting constraints favor standard TO-220 footprint and isolation is handled externally.	Select when cost-sensitive designs can accommodate additional isolation hardware and PCB layout allows non-isolated tab routing.
IPP60R190C6	650 V Si MOSFET; R_DS(on) = 0.190 Ω; higher V_DS rating but 27% higher conduction loss at 8 A.	Better suited for 400 V DC bus systems requiring 650 V margin; less optimal for 550 V-rated designs due to efficiency penalty.	Choose only if system-level overvoltage protection demands >600 V blocking, accepting 1.5 W extra conduction loss at rated current.

Compared with STP18N55M5, STF18N55M5 offers integrated electrical isolation for simplified thermal management; versus IPP60R190C6, it delivers superior efficiency in 550 V applications despite lower voltage headroom.

Availability

STF18N55M5 is available at Aetrix Electronics and suitable for industrial SMPS, server PSU PFC, and EV on-board charger designs requiring stable component supply across multi-year production cycles.

Supply support for STF18N55M5 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, designing and manufacturing analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The MDmesh™ V product line targets high-efficiency, high-power-density AC/DC and DC/DC conversion, specifically engineered to replace older planar MOSFETs in 500–650 V applications with lower R_DS(on) and faster switching.

FAQ

What is the maximum junction temperature and how does it affect continuous current rating?

The STF18N55M5 has a maximum junction temperature (T_j) of 150 °C. At T_C = 100 °C, its continuous drain current drops to 10 A due to thermal derating-this reflects real-world heatsink limitations, not device failure. Designers must use R_thj-case = 1.14 °C/W and ambient conditions to calculate actual safe operating current.

Is the TO-220FP package truly electrically isolated, and what is the test condition?

Yes-the TO-220FP tab is fully insulated from internal die structures. It is rated for 2500 V_RMS insulation withstand voltage between all three leads and external heatsink, verified under 1 second duration at T_C = 25 °C per IEC 60747-5-2. This eliminates need for mica washers or silicone pads in most industrial mounting scenarios.

How does the 100% avalanche testing impact reliability in unclamped inductive loads?

Each STF18N55M5 undergoes single-pulse avalanche stress to 210 mJ at T_j = 25 °C, ensuring guaranteed ruggedness against energy transients like transformer leakage spikes or relay contact bounce. This replaces statistical qualification and permits direct use in circuits lacking external clamping components.

Can this MOSFET be used in synchronous rectification configurations?

No-it is an N-channel high-side switch optimized for primary-side switching, not low-side synchronous rectification. Its body diode exhibits t_rr = 244 ns and Q_rr = 2.8 µC, which are too high for efficient SR operation; dedicated low-V_F, low-Q_rr Schottky or GaN devices are recommended for secondary-side rectification.

STF18N55M5 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: MDmesh™ V

Package/Case:: TO-220-3 Full Pack

Packaging:: Tube

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 550 V

Current - Continuous Drain (Id) @ 25°C:: 16A (Tc)

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

Rds On (Max) @ Id, Vgs:: 192mOhm @ 8A, 10V

Vgs(th) (Max) @ Id:: 5V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 31 nC @ 10 V

Vgs (Max):: ±25V

Input Capacitance (Ciss) (Max) @ Vds:: 1260 pF @ 100 V

FET Feature:: -

Power Dissipation (Max):: 25W (Tc)

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220FP

STF18N55M5 FAQ

1.How can I place an order for STF18N55M5 through Aetrix?

Please submit a Request for Quotation (RFQ) for STF18N55M5 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 STF18N55M5 reliable?

The price and inventory of STF18N55M5 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STF18N55M5 is usually 5 days.

3.What payment methods are accepted for STF18N55M5?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STF18N55M5 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STF18N55M5?

STF18N55M5 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STF18N55M5 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 STF18N55M5?

For technical support, including STF18N55M5 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STF18N55M5 requirements.

6.How does Aetrix verify that STF18N55M5 is sourced from the original manufacturer or authorized distributors?

All STF18N55M5 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 STF18N55M5 meets industry standards.

7.What is the process for return or replacement of STF18N55M5?

All STF18N55M5 units undergo pre-shipment inspection (PSI). If there is an issue with STF18N55M5, 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 STF18N55M5 part is unused and in its original packaging.

Return procedure for STF18N55M5:

1.Submit a request within 90 days.

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

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