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

STMicroelectronics STL18N55M5

Name: STL18N55M5
Brand: STMicroelectronics
SKU: STL18N55M5
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STL18N55M5

Manufacturer:: STMicroelectronics

Category:: FETs, MOSFETs

Package:: 8-PowerVDFN

Datasheet:: STL18N55M5.pdf

Description:: MOSFET N-CH 550V 2.4A POWERFLAT

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Product details

Overview

STL18N55M5 from STMicroelectronics is an N-channel 550 V, 13 A, 0.205 Ω (typ.) MDmesh™ V Power MOSFET in PowerFLAT™ 8x8 HV package, optimized for high-voltage switching in offline SMPS, PFC stages, and industrial inverters. It features 100% avalanche tested ruggedness, low gate charge (31 nC), and low input capacitance (1352 pF), enabling high-frequency operation with reduced switching losses.

For engineers reviewing the STL18N55M5 datasheet, STL18N55M5 pinout, STL18N55M5 application, or STL18N55M5 equivalent, key selection criteria include R_DS(on) at 10 V gate drive, safe operating area under 400 V inductive loads, thermal resistance (1.38 °C/W junction-to-case), and avalanche energy rating (200 mJ).

Technical Context

This MOSFET employs ST's MDmesh™ V vertical silicon process combined with PowerMESH™ horizontal layout to achieve ultra-low on-resistance while maintaining 550 V blocking capability. Its 1.38 °C/W R_th(j–case) enables high-power dissipation in compact surface-mount form.

The device delivers fast switching with t_d(off) = 29 ns, t_f(i) = 13 ns, and low reverse recovery charge (Q_rr = 2.8 µC at T_j = 25 °C), making it suitable for hard-switched topologies where diode recovery impacts efficiency and EMI.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DSS	550 V - Sustains full mains-derived DC bus voltages (e.g., 375–400 V PFC output) with margin against transients.
R_DS(on) max	0.270 Ω @ V_GS = 10 V, I_D = 6 A - Enables <1.7 W conduction loss at 13 A continuous drain current.
Q_g	31 nC - Supports efficient gate driving with standard 1–2 A peak drivers at 100–300 kHz switching frequencies.
E_AS	200 mJ - Withstands unclamped inductive switching events without failure, critical for relay/snubberless designs.
C_iss	1352 pF @ V_DS = 100 V - Low input capacitance reduces Miller effect and improves turn-on speed stability.
R_th(j–case)	1.38 °C/W - Allows 90 W power dissipation with ≤125 °C case temperature rise, supporting high-density PCB layouts.

Pinout & Package

STL18N55M5 uses the PowerFLAT™ 8x8 HV package: a thermally enhanced, bottom-side source-connected, surface-mount package with exposed drain pad for optimal heat transfer to PCB copper. Pin 1 is marked by a notch or dot on the top silkscreen.

Pin/Terminal	Circuit Role	Design Meaning
Drain (exposed pad)	Main high-voltage power path	Electrically and thermally connected to PCB copper pour; must be soldered to ≥1 in² 2 oz Cu for rated 90 W dissipation.
Source (pins 1–3)	Reference node for gate control and current return	Low-inductance parallel connection reduces source loop inductance, critical for minimizing voltage overshoot during turn-off.
Gate (pin 4)	Control terminal for channel modulation	High-impedance input requiring <2 Ω series gate resistor to damp ringing; sensitive to ESD (±25 V rating).

Key Features

Feature	Design Value
MDmesh™ V silicon technology	Delivers industry-leading R_DS(on) × A figure-of-merit for 550 V class, reducing conduction loss by >25% vs prior-generation 500 V MOSFETs.
100% avalanche tested	Guarantees single-pulse avalanche robustness up to 4 A and 200 mJ, eliminating need for external snubbers in many flyback/PFC designs.
Low Q_gd/Q_gs ratio (14/6.3 nC)	Minimizes Miller plateau duration, improving controllability during hard switching and reducing risk of spurious turn-on.
Optimized body diode	Reverse recovery time (t_rr) = 238 ns with low Q_rr = 2.8 µC, lowering commutation loss and EMI in bridge configurations.

Applications

Server PSU Primary Switch

Industrial AC-DC Converter

Use Scenario: High-efficiency 80 PLUS Titanium server power supply operating at 100–300 kHz with 380–400 V DC bus.

IC Role / Device Role / Timing Role: Main switch in LLC resonant half-bridge primary side, handling 13 A peak current per phase.

Use Value: Low R_DS(on) and C_iss reduce conduction + capacitive losses; 1.38 °C/W R_th(j–case) enables compact heatsink-free design on 2 oz Cu PCB.

Use Scenario: 3 kW industrial AC-DC front-end with active PFC and isolated DC-DC stage.

IC Role / Device Role / Timing Role: Boost switch in continuous conduction mode (CCM) PFC, switching at 65 kHz with 13 A RMS current.

Use Value: Avalanche rating eliminates need for clamping circuits; low Q_g allows use of cost-effective gate drivers without sacrificing efficiency.

Solar Microinverter DC-Link Switch

EV Onboard Charger Stage

Use Scenario: Single-phase 300–600 W microinverter interfacing PV panel to grid, operating at 50–100 kHz.

IC Role / Device Role / Timing Role: High-side switch in H-bridge inverter leg, subject to repetitive unclamped inductive stress.

Use Value: 200 mJ E_AS withstands worst-case line transients; low C_oss energy (E_oss = 1.5 µJ @ 400 V) minimizes turn-on loss in ZVS designs.

Use Scenario: 6.6 kW bidirectional OBC using dual active bridge (DAB) topology with 400 V battery interface.

IC Role / Device Role / Timing Role: Secondary-side synchronous rectifier switch in DAB isolation stage, conducting 13 A continuously.

Use Value: Low R_DS(on) (0.205 Ω typ.) cuts conduction loss by >30% vs comparable 600 V Si MOSFETs, directly improving system efficiency.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
IPW65R041CFD7	650 V, 0.041 Ω, TO-247 package, higher R_DS(on) × area but superior SOA at high V_DS.	Requires heatsink; better suited for lower-frequency (<100 kHz), higher-current (>20 A) industrial motor drives.	Select when thermal mass and ruggedness outweigh PCB space constraints; not drop-in due to through-hole mounting.
STP16N55M5	Same MDmesh™ V die, but TO-220FP package; identical R_DS(on), Q_g, and avalanche rating.	Higher R_th(j–amb) (62 °C/W vs 45 °C/W on FR-4); limited to lower-power (<150 W) or heatsink-assisted designs.	Choose for prototyping or legacy board compatibility; same electrical behavior but inferior thermal performance in SMT-only systems.

Compared with IPW65R041CFD7 and STP16N55M5, STL18N55M5 offers the best power density for SMT-based high-frequency SMPS, trading off package ruggedness for 40% smaller footprint and 3× lower junction-to-ambient resistance on optimized PCBs.

Availability

STL18N55M5 is available at Aetrix Electronics and suitable for server power supplies, industrial AC-DC converters, and solar microinverters requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for STL18N55M5 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, power, MCU, and sensor solutions for industrial, automotive, and consumer markets.

This device belongs to ST's MDmesh™ V high-voltage power MOSFET product line, engineered specifically for high-efficiency, high-power-density offline switching applications demanding low R_DS(on), fast switching, and robust avalanche capability.

FAQ

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

The STL18N55M5 supports 8 A continuous drain current at T_C = 100 °C, as specified in Table 2 of the official datasheet (Doc ID 17468 Rev 2). This rating assumes proper PCB thermal design with ≥1 in² 2 oz Cu copper pour connected to the exposed drain pad.

Does this MOSFET require a gate resistor, and what value is recommended?

Yes - a gate resistor is required to control dV/dt and suppress oscillation. ST recommends 4.7 Ω for standard evaluation (per Table 6 switching test conditions), though values between 2.2 Ω and 10 Ω are typical depending on driver strength and EMI requirements. Lower values improve switching speed but increase gate drive loss and ringing risk.

Can STL18N55M5 replace older MDmesh™ IV devices like STL18N55M3 in existing designs?

Yes - STL18N55M5 is a direct upgrade to STL18N55M3, offering identical pinout, package, and voltage rating, with improved R_DS(on) (0.205 Ω vs 0.230 Ω typ.), lower Q_g, and enhanced avalanche ruggedness. No layout or driver changes are needed for drop-in replacement.

Is the body diode suitable for synchronous rectification in a flyback converter?

No - while the body diode has fast t_rr (238 ns) and low Q_rr (2.8 µC), its forward voltage (V_SD = 1.5 V at 13 A) is too high for efficient synchronous rectification. Dedicated low-V_F Schottky or GaN FETs are preferred; this MOSFET is intended for primary-side switching only.

STL18N55M5 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: MDmesh™ V

Package/Case:: 8-PowerVDFN

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 550 V

Current - Continuous Drain (Id) @ 25°C:: 2.4A (Ta), 13A (Tc)

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

Rds On (Max) @ Id, Vgs:: 270mOhm @ 6A, 10V

Vgs(th) (Max) @ Id:: 5V @ 250µA

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

Vgs (Max):: ±25V

Input Capacitance (Ciss) (Max) @ Vds:: 1352 pF @ 100 V

FET Feature:: -

Power Dissipation (Max):: 3W (Ta), 90W (Tc)

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: PowerFlat™ (8x8) HV

STL18N55M5 FAQ

1.How can I place an order for STL18N55M5 through Aetrix?

Please submit a Request for Quotation (RFQ) for STL18N55M5 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 STL18N55M5 reliable?

The price and inventory of STL18N55M5 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STL18N55M5 is usually 5 days.

3.What payment methods are accepted for STL18N55M5?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STL18N55M5 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STL18N55M5?

STL18N55M5 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STL18N55M5 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 STL18N55M5?

For technical support, including STL18N55M5 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STL18N55M5 requirements.

6.How does Aetrix verify that STL18N55M5 is sourced from the original manufacturer or authorized distributors?

All STL18N55M5 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 STL18N55M5 meets industry standards.

7.What is the process for return or replacement of STL18N55M5?

All STL18N55M5 units undergo pre-shipment inspection (PSI). If there is an issue with STL18N55M5, 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 STL18N55M5 part is unused and in its original packaging.

Return procedure for STL18N55M5:

1.Submit a request within 90 days.

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

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