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

STMicroelectronics STW40NF20

Name: STW40NF20
Brand: STMicroelectronics
SKU: STW40NF20
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STW40NF20

Manufacturer:: STMicroelectronics

Category:: FETs, MOSFETs

Package:: TO-247-3

Datasheet:: STW40NF20.pdf

Description:: MOSFET N-CH 200V 40A TO247-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

STW40NF20 from STMicroelectronics is an N-channel enhancement-mode Power MOSFET in TO-247 package, rated for 200V V_DSS, 40A continuous drain current at T_C = 25°C, and 0.038Ω R_DS(on) at V_GS = 10V. It features low gate charge (Q_g = 75nC), high avalanche ruggedness (E_AS = 230mJ), and is optimized as a primary-side switch in isolated DC-DC converters.

For engineers reviewing the STW40NF20 datasheet, STW40NF20 pinout, STW40NF20 application, or STW40NF20 equivalent, key selection criteria include its 200V breakdown voltage, 0.038Ω on-resistance at 10V gate drive, 75nC total gate charge, 160W power dissipation capability, and TO-247 thermal performance (R_thj-case = 0.78°C/W).

Technical Context

This STripFET™ II device uses a planar vertical structure with minimized input capacitance (C_iss = 2500pF) and reverse transfer capacitance (C_rss = 78pF), enabling fast switching (t_d(on) = 20ns, t_f = 22ns) under 4.7Ω gate resistance. Its low R_DS(on) × Q_g figure of merit supports high-efficiency operation in hard-switched topologies.

The integrated source-drain diode exhibits t_rr = 192ns and Q_rr = 922nC at 25°C, with controlled recovery characteristics suitable for synchronous rectification and flyback snubberless designs. 100% unclamped inductive switching (UIS) testing ensures robustness in real-world transient conditions.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DSS	200V - Withstands up to 200V drain-source blocking voltage before avalanche conduction.
R_DS(on)	0.038Ω @ V_GS = 10V - Enables <1.5W conduction loss at 20A, critical for thermal management in high-current SMPS.
Q_g	75nC - Low gate charge reduces driver power requirement and enables efficient 100–500kHz switching in LLC and phase-shifted full-bridge converters.
P_tot	160W @ T_C = 25°C - High power handling supports high-output industrial and telecom power supplies without forced cooling.
R_thj-case	0.78°C/W - Enables junction-to-heatsink temperature rise of only 125°C at 160W, supporting reliable operation with standard TO-247 heatsinking.
E_AS	230mJ - Single-pulse avalanche energy rating allows safe operation during inductive turn-off transients without external clamping.
C_iss	2500pF @ V_DS = 25V - Low input capacitance minimizes Miller effect and improves gate drive efficiency in high-frequency applications.

Pinout & Package

STW40NF20 is housed in a TO-247 package with three leads: Gate (pin 1), Drain (pin 2), Source (pin 3). The metal tab is electrically connected to the Drain terminal and serves as the primary heat transfer path to the heatsink. Mounting requires insulated hardware due to drain potential.

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (Gate)	Control electrode	Receives 10V logic-level gate drive; low input capacitance (2500pF) enables fast turn-on with minimal driver stress.
Pin 2 (Drain)	Main power output terminal	Connected to high-voltage rail (up to 200V); metal tab is electrically tied to this pin and must be isolated from chassis ground.
Pin 3 (Source)	Reference node / return path	Serves as common reference for gate drive and load current return; low-inductance layout essential to minimize switching oscillation.

Key Features

Feature	Design Value
Low R_DS(on) × Q_g FoM	2.85 Ω·nC - Optimized trade-off between conduction loss and switching loss for 100–300kHz DC-DC primary switches.
100% UIS tested	40A I_AR, 230mJ E_AS - Guarantees ruggedness against inductive turn-off spikes without external protection components.
Low C_rss/C_iss ratio	78pF / 2500pF = 3.1% - Reduces Miller-induced false turn-on risk in high-dv/dt environments like bridge-leg configurations.
ECOPACK® compliant	Lead-free second-level interconnect per JEDEC JESD97 - Meets RoHS and WEEE requirements for industrial and telecom equipment.
High dV/dt immunity	12V/ns - Resists parasitic turn-on during fast voltage transitions in high-side or half-bridge configurations.

Applications

Telecom AC-DC Front-End

Industrial Motor Drive Inverter

Use Scenario: Primary switch in 1–3kW telecom rectifier modules converting 380VAC to +48VDC via PFC + LLC stages.

IC Role / Device Role / Timing Role: High-voltage, high-current main switch in LLC resonant half-bridge primary side, operating at 200–350kHz.

Use Value: 0.038Ω R_DS(on) and 75nC Q_g enable >96% peak efficiency while maintaining thermal margin on passive heatsinks.

Use Scenario: Phase-leg switch in 5–15kW variable-frequency drives powering HVAC compressors and pumps.

IC Role / Device Role / Timing Role: 200V N-channel MOSFET in 3-phase inverter bridge, commutating up to 40A RMS motor current.

Use Value: 230mJ E_AS rating eliminates need for external snubbers during motor short-circuit fault events.

Server PSU Primary Side

EV Onboard Charger (OBC) PFC Stage

Use Scenario: Switch in 1.5–2kW server power supply with active clamp forward or phase-shifted full-bridge topology.

IC Role / Device Role / Timing Role: Main switching element handling 40A pulsed drain current with 160W dissipation capability.

Use Value: 0.78°C/W R_thj-case allows direct mounting to cold plate, reducing thermal interface layers and system BOM cost.

Use Scenario: Boost switch in 6.6kW single-phase OBC PFC stage operating at 65–100kHz.

IC Role / Device Role / Timing Role: High-reliability 200V switch managing 35A average input current with high dv/dt immunity.

Use Value: 12V/ns dv/dt rating prevents spurious turn-on during fast line-voltage zero-crossings in grid-connected systems.

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
IRFP460PBF	200V V_DSS, 0.27Ω R_DS(on), 130nC Q_g, TO-247 - Higher on-resistance and gate charge than STW40NF20.	Higher conduction and switching losses limit use to ≤100kHz applications; less suitable for high-density telecom PSUs.	Select when legacy design compatibility or availability outweighs efficiency targets.
IXFH40N20P	200V V_DSS, 0.042Ω R_DS(on), 92nC Q_g, TO-247 - Slightly higher R_DS(on) and Q_g than STW40NF20.	Lower figure of merit increases driver losses and thermal stress in 300kHz+ LLC designs.	Prefer for designs requiring extended SOA curves or higher T_j derating above 150°C.

Compared with IRFP460PBF and IXFH40N20P, STW40NF20 delivers superior R_DS(on) × Q_g performance (2.85 vs. 35.1 and 3.86 Ω·nC), enabling higher frequency operation with lower thermal footprint in space-constrained power supplies.

Availability

STW40NF20 is available at Aetrix Electronics and suitable for telecom rectifiers, industrial motor drives, server power supplies, and EV onboard chargers requiring stable component supply across multi-year production cycles.

Supply support for STW40NF20 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.

STW40NF20 belongs to the STripFET™ II Power MOSFET product line, engineered specifically to reduce gate charge and input capacitance for high-efficiency, high-frequency switched-mode power supplies.

FAQ

What is the maximum continuous drain current for STW40NF20 at 100°C case temperature?

The maximum continuous drain current is 25A at T_C = 100°C, as specified in Table 1 of the datasheet. This derating reflects thermal limitations of the TO-247 package and silicon die, requiring proper heatsinking to sustain full 40A operation only at T_C ≤ 25°C.

Does STW40NF20 require a negative gate turn-off voltage?

No. STW40NF20 is a standard enhancement-mode N-channel MOSFET with V_GS(th) = 2–4V and operates reliably with 0V/10V gate drive. A negative turn-off voltage is not required, though –5V may improve noise immunity in high-dv/dt environments.

Can STW40NF20 be used in parallel configurations?

Yes - its positive temperature coefficient of R_DS(on) (confirmed in Figure 15) enables stable current sharing. Parallel operation requires matched gate drive impedance, symmetrical PCB layout, and individual gate resistors to suppress oscillation.

Is STW40NF20 suitable for linear mode (LDO or regulator) operation?

No. While it can withstand brief linear-mode stress, its Safe Operating Area (SOA) curve (Figure 4) shows limited DC capability beyond 10V V_DS. It is designed exclusively for switching applications, not linear regulation.

STW40NF20 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: STripFET™

Package/Case:: TO-247-3

Packaging:: Tube

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 200 V

Current - Continuous Drain (Id) @ 25°C:: 40A (Tc)

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

Rds On (Max) @ Id, Vgs:: 45mOhm @ 20A, 10V

Vgs(th) (Max) @ Id:: 4V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 75 nC @ 10 V

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 2500 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 160W (Tc)

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-247-3

STW40NF20 FAQ

1.How can I place an order for STW40NF20 through Aetrix?

Please submit a Request for Quotation (RFQ) for STW40NF20 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 STW40NF20 reliable?

The price and inventory of STW40NF20 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STW40NF20 is usually 5 days.

3.What payment methods are accepted for STW40NF20?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STW40NF20 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STW40NF20?

STW40NF20 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STW40NF20 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 STW40NF20?

For technical support, including STW40NF20 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STW40NF20 requirements.

6.How does Aetrix verify that STW40NF20 is sourced from the original manufacturer or authorized distributors?

All STW40NF20 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 STW40NF20 meets industry standards.

7.What is the process for return or replacement of STW40NF20?

All STW40NF20 units undergo pre-shipment inspection (PSI). If there is an issue with STW40NF20, 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 STW40NF20 part is unused and in its original packaging.

Return procedure for STW40NF20:

1.Submit a request within 90 days.

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

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