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

STMicroelectronics STP9NM40N

Name: STP9NM40N
Brand: STMicroelectronics
SKU: STP9NM40N
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STP9NM40N

Manufacturer:: STMicroelectronics

Category:: FETs, MOSFETs

Package:: TO-220-3

Datasheet:: STP9NM40N.pdf

Description:: MOSFET N-CH 400V 5.6A TO220

Quantity:: RFQ Add To RFQ list

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Product details

Overview

STP9NM40N from STMicroelectronics is an N-channel 400 V, 5.6 A MDmesh™ II Power MOSFET in TO-220 package, featuring 0.73 Ω typ. R_DS(on), 14 nC total gate charge, and 100% avalanche tested. It serves as a high-efficiency primary-side switch in offline SMPS, PFC stages, and industrial DC-DC converters operating up to 150 °C junction temperature.

For engineers reviewing the STP9NM40N datasheet, STP9NM40N pinout, STP9NM40N application, or STP9NM40N equivalent, this device is selected for high-voltage switching where low conduction loss, fast switching (t_r = 4.4 ns), robust diode recovery (t_rr = 187 ns at T_j = 25 °C), and reliable unclamped inductive switching capability are critical.

Technical Context

This MOSFET employs ST's second-generation MDmesh™ vertical strip architecture to minimize both R_DS(on) and gate charge simultaneously-achieving 0.73 Ω @ 10 V_GS and Q_g = 14 nC. Its 400 V V_DSS rating and 140 mJ single-pulse avalanche energy support operation in 380 V DC bus applications with margin.

The device integrates a fast, low-loss body diode (V_SD = 1.5 V @ 5.6 A, t_rr = 187 ns) optimized for hard-switched topologies. Thermal resistance R_thj-case = 2.08 °C/W enables 60 W dissipation at T_C = 25 °C without forced cooling.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DSS	400 V - supports 380 V DC bus with 5% margin in industrial SMPS and PFC designs
R_DS(on) typ.	0.73 Ω @ V_GS = 10 V, I_D = 2.5 A - enables <1.1 W conduction loss at 5.6 A continuous current
Q_g	14 nC - reduces gate drive power and allows use of low-cost 1 W drivers in 100 kHz–300 kHz converters
t_r / t_f	4.4 ns / 8.8 ns @ V_DD = 200 V, R_G = 4.7 Ω - minimizes switching transition losses in high-frequency operation
E_AS	140 mJ - ensures ruggedness against inductive turn-off transients without external snubbers
T_j max	150 °C - permits operation in sealed enclosures or high-ambient environments without derating

Pinout & Package

STP9NM40N is housed in a TO-220 package with standard 3-pin configuration: Drain (Tab), Gate (Pin 1), Source (Pin 2). The metal tab is electrically connected to the Drain terminal and must be isolated from heatsink unless circuit topology requires drain-to-heatsink connection.

Pin/Terminal	Circuit Role	Design Meaning
Tab (Drain)	Main high-side current path	High-current drain connection; thermally coupled to case for efficient heat transfer to heatsink
Pin 1	Gate	Low-impedance control input requiring ≤5.4 Ω intrinsic gate resistance; sensitive to ESD
Pin 2	Source	Reference node for gate drive; carries full load current and forms return path for body diode conduction

Key Features

Feature	Design Value
100% avalanche tested	Guarantees minimum 140 mJ single-pulse energy handling under unclamped inductive switching, eliminating need for overdesign
Low Q_g / R_DS(on) ratio	19.2 nC/Ω - improves figure-of-merit for high-frequency, high-efficiency converters vs. legacy planar MOSFETs
Fast body diode recovery	t_rr = 187 ns, Q_rr = 1.3 µC - reduces reverse recovery losses and EMI in bridge configurations
Low C_iss / C_oss	365 pF / 30 pF @ 50 V - enables stable gate drive with minimal Miller effect and reduced dv/dt-induced turn-on risk

Applications

Industrial SMPS

AC-DC Adapters

Use Scenario: Primary-side switch in 100–300 W open-frame industrial power supplies with universal AC input.

IC Role / Device Role / Timing Role: High-voltage switching element in flyback or forward converter operating at 65–130 kHz.

Use Value: 0.73 Ω R_DS(on) and 14 nC Q_g reduce total losses by ≥12% versus comparable 450 V MOSFETs, enabling >90% efficiency at full load.

Use Scenario: Main switch in compact 65 W laptop adapters with active PFC + LLC secondary stage.

IC Role / Device Role / Timing Role: PFC boost switch handling 5.6 A continuous current at 100 kHz with 400 V blocking.

Use Value: 140 mJ E_AS withstands line surge events without failure; 2.08 °C/W R_thj-case allows natural convection cooling.

Motor Drive Inverters

LED Street Lighting

Use Scenario: Half-bridge upper-leg switch in 750 W BLDC motor drives for HVAC blowers and pumps.

IC Role / Device Role / Timing Role: High-side switching device subjected to 300 V DC bus and 22.4 A pulsed current.

Use Value: 22.4 A I_DM and 40 V/ns dv/dt immunity prevent false triggering during commutation; robust body diode handles freewheeling.

Use Scenario: Primary switch in 150 W constant-current LED driver for outdoor street lighting with surge immunity.

IC Role / Device Role / Timing Role: Flyback switch operating across wide ambient range (−40 °C to +85 °C) with 150 °C T_j rating.

Use Value: R_DS(on) variation <±15% from −50 °C to 150 °C ensures stable output regulation; ECOPACK® RoHS-compliant packaging meets outdoor environmental specs.

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage N-channel MOSFET applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
STP10NK40Z	400 V, 10 A, R_DS(on) = 0.42 Ω typ., Q_g = 25 nC, Zener-protected gate	Higher current rating but larger gate charge increases drive loss at >100 kHz	Prefer when higher I_D headroom is needed and switching frequency ≤65 kHz
FQP4N40	400 V, 4 A, R_DS(on) = 1.6 Ω typ., Q_g = 12 nC, planar process	Lower cost but 2.2× higher R_DS(on) and no avalanche rating	Acceptable only in low-power (<30 W), non-critical, cost-driven designs without surge requirements

Compared with STP10NK40Z and FQP4N40, STP9NM40N delivers optimal balance of conduction efficiency (0.73 Ω), switching speed (14 nC), and ruggedness (140 mJ E_AS) for 50–300 W industrial converters where thermal margin and reliability are prioritized over raw current rating or lowest BOM cost.

Availability

STP9NM40N is available at Aetrix Electronics and suitable for industrial SMPS, AC-DC adapters, and LED street lighting systems requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for STP9NM40N 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 microcontrollers, power devices, sensors, and analog ICs for industrial, automotive, and consumer markets.

STP9NM40N belongs to the MDmesh™ II Power MOSFET product line, engineered specifically for high-efficiency, high-voltage switching in offline power conversion-emphasizing low R_DS(on), low Q_g, and avalanche ruggedness.

FAQ

Is STP9NM40N suitable for use in PFC boost circuits?

Yes. With its 400 V V_DSS, 5.6 A continuous current rating, 0.73 Ω R_DS(on), and 14 nC Q_g, STP9NM40N is validated for continuous conduction mode (CCM) PFC stages up to 300 W. Its fast body diode (t_rr = 187 ns) and 140 mJ avalanche energy ensure robustness against line surges and inductive kickback during zero-crossing transitions.

What is the maximum recommended gate resistor value for 100 kHz operation?

For 100 kHz hard-switching with minimal overshoot, a gate resistor of 4.7 Ω is specified in the datasheet test conditions (t_r/t_f measured with R_G = 4.7 Ω). Using >10 Ω increases switching time and losses; <2.2 Ω risks ringing and excessive peak gate current (>2 A) with typical 12 V drivers.

Does STP9NM40N require a gate driver IC, or can it be driven directly from a microcontroller?

A microcontroller GPIO cannot safely drive STP9NM40N. Its 14 nC Q_g and 5.4 Ω intrinsic gate resistance demand ≥100 mA peak current for sub-100 ns turn-on. A dedicated gate driver (e.g., STMicro's STGAP2S) is required to achieve rated switching performance and avoid shoot-through or thermal runaway.

How does the TO-220 package compare thermally to the DPAK version (STD9NM40N)?

STP9NM40N in TO-220 has R_thj-case = 2.08 °C/W, while STD9NM40N in DPAK has R_thj-case = 2.08 °C/W (identical per datasheet Table 3), but DPAK's R_thj-pcb = 50 °C/W limits PCB-only cooling. TO-220's larger tab enables direct heatsink mounting, delivering up to 60 W at T_C = 25 °C-versus ~2.5 W for DPAK on 1-in² 2-oz copper.

STP9NM40N 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):: 400 V

Current - Continuous Drain (Id) @ 25°C:: 5.6A (Tc)

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

Rds On (Max) @ Id, Vgs:: 790mOhm @ 2.5A, 10V

Vgs(th) (Max) @ Id:: 4V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 14 nC @ 10 V

Vgs (Max):: ±25V

Input Capacitance (Ciss) (Max) @ Vds:: 365 pF @ 50 V

FET Feature:: -

Power Dissipation (Max):: 60W (Tc)

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

STP9NM40N FAQ

1.How can I place an order for STP9NM40N through Aetrix?

Please submit a Request for Quotation (RFQ) for STP9NM40N 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 STP9NM40N reliable?

The price and inventory of STP9NM40N are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STP9NM40N is usually 5 days.

3.What payment methods are accepted for STP9NM40N?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STP9NM40N transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STP9NM40N?

STP9NM40N orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STP9NM40N 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 STP9NM40N?

For technical support, including STP9NM40N datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STP9NM40N requirements.

6.How does Aetrix verify that STP9NM40N is sourced from the original manufacturer or authorized distributors?

All STP9NM40N 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 STP9NM40N meets industry standards.

7.What is the process for return or replacement of STP9NM40N?

All STP9NM40N units undergo pre-shipment inspection (PSI). If there is an issue with STP9NM40N, 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 STP9NM40N part is unused and in its original packaging.

Return procedure for STP9NM40N:

1.Submit a request within 90 days.

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

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