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

STMicroelectronics STP5NK40Z

Name: STP5NK40Z
Brand: STMicroelectronics
SKU: STP5NK40Z
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STP5NK40Z

Manufacturer:: STMicroelectronics

Category:: FETs, MOSFETs

Package:: TO-220-3

Datasheet:: STP5NK40Z.pdf

Description:: MOSFET N-CH 400V 3A TO220AB

Quantity:: RFQ Add To RFQ list

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Inventory:4,956

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Product details

Overview

STP5NK40Z from STMicroelectronics is an N-channel 400 V, 1.47 Ω (typ), 3 A Zener-protected SuperMESH™ power MOSFET in TO-220 package, designed for high-voltage switching in offline AC-DC power supplies and PFC stages. It features 100% avalanche tested ruggedness, 4.5 V/ns dv/dt capability, and integrated gate-source Zener diodes for ESD and transient protection.

For engineers reviewing the STP5NK40Z datasheet, STP5NK40Z pinout, STP5NK40Z application, or STP5NK40Z equivalent, key selection criteria include its 400 V V_DSS, 1.47 Ω R_DS(on) at V_GS = 10 V, 45 W P_TOT, 130 mJ E_AS, and TO-220 thermal resistance of 2.77 °C/W - all critical for reliable high-speed, high-voltage switching in industrial and consumer power systems.

Technical Context

This MOSFET employs ST's optimized strip-based PowerMESH™ layout to achieve low on-resistance while maintaining exceptional dv/dt immunity (4.5 V/ns) and robust unclamped inductive switching performance. Its built-in back-to-back gate-source Zener diodes (±30 V breakdown) eliminate external protection components and enhance system-level ESD resilience (2800 V HBM).

The device operates with a gate threshold voltage of 3.0–4.5 V and delivers 2.2 S forward transconductance at 1.5 A. Its dynamic parameters - including 11.7 nC total gate charge, 305 pF C_iss, and 44 pF C_oss(eq) - support efficient high-frequency switching up to several hundred kHz in hard-switched topologies.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DSS	400 V - supports full-wave rectified 230 VAC input (≈325 V peak) with margin for surge and ringing.
R_DS(on)	1.47 Ω (typ) at V_GS = 10 V - enables <3 W conduction loss at 1.5 A, suitable for 3 A continuous operation at TC = 25°C.
I_D (cont)	3 A at T_C = 25°C - rated for medium-power SMPS primary-side switching with heatsink-assisted thermal management.
E_AS	130 mJ (single-pulse) - ensures survivability during unclamped inductive turn-off events in PFC and flyback circuits.
dv/dt	4.5 V/ns - prevents spurious turn-on in high-noise, fast-switching environments such as boost PFC stages.
Q_g	11.7 nC - enables efficient gate drive with standard 1 A peak drivers, reducing switching losses at 100–300 kHz.
R_thj-case	2.77 °C/W - allows junction temperature rise of ≤125°C with 45 W dissipation and 45°C case temperature rise.

Pinout & Package

STP5NK40Z is housed in a through-hole TO-220 package with isolated tab (drain-connected), offering mechanical robustness and straightforward heatsinking. The three-terminal configuration supports high-current PCB mounting with minimal parasitic inductance.

Pin/Terminal	Circuit Role	Design Meaning
1 (Source)	Power return path for load current	Low-impedance source node; connects directly to ground plane or low-side shunt for sensing and stability.
2 (Gate)	Control input for channel conduction	High-impedance MOS control terminal; requires RC snubber or gate resistor (4.7 Ω typical) to damp ringing and limit di/dt.
3 (Drain)	Main high-voltage power output node	Internally connected to metal tab; electrically isolated but thermally coupled - must be insulated from heatsink unless referenced to same potential.

Key Features

Feature	Design Value
Zener-protected gate	Integrated ±30 V gate-source Zener clamps prevent overvoltage damage during handling and board-level transients without external components.
100% avalanche tested	Every unit validated for unclamped inductive energy handling (I_AR = 3 A, E_AS = 130 mJ), ensuring field reliability in PFC and flyback applications.
SuperMESH™ layout	Optimized cell structure achieves 1.47 Ω R_DS(on) at 400 V while retaining high dv/dt immunity - rare combination in high-voltage MOSFETs.
Low C_oss(eq)	44 pF equivalent output capacitance reduces turn-off loss and improves efficiency in hard-switched converters operating above 100 kHz.

Applications

Offline AC-DC Adapters

Active PFC Boost Stages

Use Scenario: 36–65 W universal-input wall adapters with primary-side PWM control and diode rectification.

IC Role / Device Role: Main switch in discontinuous conduction mode (DCM) flyback converter, handling 3 A peak drain current at 400 V blocking.

Use Value: Low R_DS(on) minimizes conduction loss; avalanche rating absorbs leakage inductance spikes without snubber redesign.

Use Scenario: 100–200 W boost PFC front-end for LED drivers and industrial SMPS.

IC Role / Device Role: High-side switching element in continuous conduction mode (CCM) boost circuit, switching at 65–133 kHz.

Use Value: 4.5 V/ns dv/dt capability prevents false triggering from fast-rising V_DS edges; low Q_g eases gate driver sizing.

LED Driver Power Stages

Industrial DC-DC Converters

Use Scenario: Constant-current buck/boost LED drivers for street lighting and high-bay fixtures (230 VAC input).

IC Role / Device Role: Primary switch regulating average LED current via PWM dimming-compatible high-frequency operation.

Use Value: Integrated Zener protection eliminates need for external TVS on gate, reducing BOM count and layout area in space-constrained enclosures.

Use Scenario: Isolated dual-output DC-DC modules (24 V/12 V) for PLC I/O and sensor interfaces.

IC Role / Device Role: Primary-side switch in forward or half-bridge topology, operating under wide ambient temperature range (−40°C to +85°C).

Use Value: Stable R_DS(on) vs. temperature (±15% from −55°C to 150°C) ensures predictable thermal derating and consistent efficiency across operating conditions.

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
STP5NK50Z	500 V V_DSS, 1.8 Ω R_DS(on), same TO-220 package and Zener protection	Higher voltage margin for 400 VAC systems or long-line surges; slightly higher conduction loss	Select when system requires >400 V blocking headroom without changing layout or drive.
FQP3N40	400 V V_DSS, 2.2 Ω R_DS(on), no integrated Zener, lower E_AS (95 mJ)	Lacks gate protection and avalanche ruggedness; requires external gate clamp and careful SOA design	Choose only in cost-sensitive, low-risk applications with controlled gate drive and low di/dt.

Compared with STP5NK50Z and FQP3N40, STP5NK40Z offers the optimal balance of 400 V rating, low 1.47 Ω on-resistance, guaranteed avalanche energy, and integrated Zener protection - making it preferred for production-grade offline power where reliability and design simplicity are prioritized.

Availability

STP5NK40Z is available at Aetrix Electronics and suitable for offline AC-DC adapters, active PFC boost stages, and industrial DC-DC converters requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for STP5NK40Z 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 management, microcontrollers, sensors, and automotive ICs.

The SuperMESH™ MOSFET product line targets high-efficiency, high-reliability power conversion in consumer, industrial, and lighting applications - emphasizing ruggedness, low loss, and ease of use in demanding high-voltage switching environments.

FAQ

Is STP5NK40Z pin-compatible with STD5NK40Z?

No - STP5NK40Z uses TO-220 (3-pin, drain-connected tab), while STD5NK40Z is in DPAK (TO-252) with exposed drain pad on bottom. Pin numbering differs: TO-220 is G-S-D (1-2-3), DPAK is G-D-S (1-2-3). Mechanical and thermal interfaces are incompatible without PCB redesign.

What is the maximum safe operating temperature for continuous operation?

The absolute maximum junction temperature is 150°C. For continuous 3 A operation, case temperature must remain ≤75°C to stay within the 45 W P_TOT derating curve (0.36 W/°C), assuming R_thj-case = 2.77 °C/W. Ambient temperature should not exceed 50°C with adequate heatsinking.

Does STP5NK40Z require a gate resistor, and what value is recommended?

Yes - a gate resistor is required to control switching speed and suppress oscillation. ST recommends 4.7 Ω for resistive loads (Figure 3) and 10–22 Ω for inductive loads (Figure 5) to limit peak gate current and manage EMI. Lower values increase dv/dt stress; higher values raise switching losses.

Can STP5NK40Z replace STP12NK40Z in an existing design?

No - STP12NK40Z has 12 A rating and 0.42 Ω R_DS(on); substituting STP5NK40Z (3 A, 1.47 Ω) would cause excessive conduction loss and thermal runaway under identical load. It is not a drop-in replacement; redesign of gate drive, heatsink, and SOA margins is mandatory.

STP5NK40Z Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: SuperMESH™

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:: 3A (Tc)

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

Rds On (Max) @ Id, Vgs:: 1.8Ohm @ 1.5A, 10V

Vgs(th) (Max) @ Id:: 4.5V @ 50µA

Gate Charge (Qg) (Max) @ Vgs:: 17 nC @ 10 V

Vgs (Max):: ±30V

Input Capacitance (Ciss) (Max) @ Vds:: 305 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 45W (Tc)

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

STP5NK40Z FAQ

1.How can I place an order for STP5NK40Z through Aetrix?

Please submit a Request for Quotation (RFQ) for STP5NK40Z 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 STP5NK40Z reliable?

The price and inventory of STP5NK40Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STP5NK40Z is usually 5 days.

3.What payment methods are accepted for STP5NK40Z?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STP5NK40Z transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STP5NK40Z?

STP5NK40Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STP5NK40Z 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 STP5NK40Z?

For technical support, including STP5NK40Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STP5NK40Z requirements.

6.How does Aetrix verify that STP5NK40Z is sourced from the original manufacturer or authorized distributors?

All STP5NK40Z 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 STP5NK40Z meets industry standards.

7.What is the process for return or replacement of STP5NK40Z?

All STP5NK40Z units undergo pre-shipment inspection (PSI). If there is an issue with STP5NK40Z, 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 STP5NK40Z part is unused and in its original packaging.

Return procedure for STP5NK40Z:

1.Submit a request within 90 days.

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

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