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

STMicroelectronics STD5NK50Z-1

Name: STD5NK50Z-1
Brand: STMicroelectronics
SKU: STD5NK50Z-1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STD5NK50Z-1

Manufacturer:: STMicroelectronics

Category:: FETs, MOSFETs

Package:: TO-251-3 Short Leads, IPAK, TO-251AA

Datasheet:: STD5NK50Z-1.pdf

Description:: MOSFET N-CH 500V 4.4A IPAK

Quantity:: RFQ Add To RFQ list

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Inventory:8,051

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Product details

Overview

STD5NK50ZT4 from STMicroelectronics is a Zener-protected N-channel 500 V SuperMESH™ Power MOSFET in DPAK (TO-252) package, with 1.22 Ω typical R_DS(on), 4.4 A continuous drain current at T_C = 25 °C, and 100% avalanche tested. It serves as a high-voltage switching device in offline SMPS, AC-DC adapters, and industrial motor control circuits.

For engineers reviewing the STD5NK50ZT4 datasheet, STD5NK50ZT4 pinout, STD5NK50ZT4 application, or STD5NK50ZT4 equivalent, key selection factors include its 4.5 V/ns dv/dt capability, built-in gate-source Zener protection (±30 V), low 20 nC total gate charge, and 130 mJ single-pulse avalanche energy - critical for rugged flyback and PFC stage design.

Technical Context

This MOSFET employs ST's SuperMESH™ process to reduce on-resistance while maintaining high dv/dt immunity (4.5 V/ns) and robust unclamped inductive switching performance. Its intrinsic capacitances - C_iss = 535 pF, C_oss = 75 pF, C_rss = 17 pF - are optimized for fast, low-loss hard-switching operation in 50–100 kHz power converters.

The integrated back-to-back gate-source Zener diodes provide ±30 V breakdown protection without external clamps, and the source-drain diode supports 4.4 A continuous conduction with 310 ns reverse recovery time (T_j = 150 °C), enabling quasi-resonant and synchronous rectification roles in compact topologies.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	500 V - Supports full mains input (85–265 V_AC) with margin for voltage spikes in offline converters.
R_DS(on) typ.	1.22 Ω - Enables <1.2 W conduction loss at 4.4 A, reducing heatsink requirements in space-constrained designs.
Q_g	20 nC - Low gate drive power demand; compatible with standard PWM controllers (e.g., UC384x, L6565) without gate driver boost.
E_AS	130 mJ - Withstands repetitive unclamped inductive switching events in PFC and flyback snubberless configurations.
T_j max	150 °C - Allows operation in sealed enclosures or high-ambient environments (e.g., industrial power supplies, LED drivers).
C_oss eq.	45 pF - Minimizes turn-off energy loss and improves efficiency in high-frequency (>65 kHz) resonant topologies.
V_(BR)GSO	±30 V - Eliminates need for external gate Zener clamp, simplifying layout and improving ESD robustness (3 kV HBM).

Pinout & Package

DPAK (TO-252) package: surface-mount, thermally enhanced with exposed drain tab (pin 2) for PCB copper pour thermal coupling. Standard footprint per Figure 24 (DS2834 Rev 6, p.15); recommended pad size: 5.2 mm × 6.5 mm for optimal R_thj-pcb = 50 °C/W.

Pin/Terminal	Circuit Role	Design Meaning
1 (G)	Gate	Control terminal; accepts 10 V logic-level drive; Zener-protected to ±30 V for transient immunity.
2 (D)	Drain	Main high-side switching node; electrically connected to exposed tab - must be isolated from heatsink unless floating.
3 (S)	Source	Power return path and reference for gate drive; ties to ground or low-side switch source in half-bridge configurations.

Key Features

Feature	Design Value
100% avalanche tested	Guarantees minimum 130 mJ single-pulse energy handling under worst-case unclamped inductive load conditions.
SuperMESH™ technology	Reduces R_DS(on) by ~25% vs. prior PowerMESH™ generation while preserving dv/dt immunity and SOA stability.
Zener-protected gate	Integrated ±30 V gate-source Zener eliminates external TVS, cutting BOM count and layout area in cost-sensitive adapters.
Low Q_g/Q_gd ratio	Q_gd = 10 nC of total 20 nC Q_g enables clean Miller plateau control and reduced switching oscillation in high-dV/dt layouts.
Optimized C_oss eq.	45 pF equivalent output capacitance minimizes turn-off loss and improves light-load efficiency in QR flyback designs.

Applications

AC-DC Adapter Primary Switch

Industrial PFC Boost Stage

Use Scenario: 36 W universal-input adapter with QR flyback topology operating at 65 kHz.

IC Role / Device Role / Timing Role: High-side main switch; handles 500 V blocking and 4.4 A peak primary current during demagnetization.

Use Value: 1.22 Ω R_DS(on) limits conduction loss to <1.1 W at full load, enabling natural convection cooling without heatsink.

Use Scenario: 300 W active PFC front-end in industrial PLC power supply.

IC Role / Device Role / Timing Role: Boost switch; commutates at 65–100 kHz with 4.5 V/ns dv/dt immunity to prevent false turn-on during line transients.

Use Value: 130 mJ E_AS withstands repeated inductor current interruption during brownout recovery without failure.

LED Driver Flyback Switch

Motor Control Protection FET

Use Scenario: 25 W constant-current LED driver for street lighting with wide ambient range (−40 to +85 °C).

IC Role / Device Role / Timing Role: Primary-side switching element; operates with 150 °C max junction temperature rating under sustained overload.

Use Value: 100% avalanche testing ensures reliability during LED string open-circuit fault events that induce high-energy voltage spikes.

Use Scenario: Overvoltage clamp in 24 V DC brushed motor H-bridge driver module.

IC Role / Device Role / Timing Role: Crowbar protection FET; triggered by comparator during bus overvoltage to short excess energy to ground.

Use Value: Fast 310 ns t_rr and 9.2 A I_RRM enable rapid energy diversion before downstream IC damage occurs.

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	Same die, TO-220 package; R_thj-case = 1.78 °C/W vs. DPAK's 5.0 °C/W; higher ID_cont at TC = 100 °C (2.7 A vs. 2.7 A same).	Requires through-hole assembly and mechanical heatsink mounting; better suited for prototyping or lower-volume industrial modules.	Select when board-level thermal management is impractical and discrete heatsinking is preferred.
FQP5N50	500 V, 1.4 Ω R_DS(on), 4.5 A; no built-in Zener protection; C_iss = 650 pF; E_AS not specified in datasheet.	Lacks gate Zener and avalanche rating confirmation; requires external gate clamp and careful SOA derating in demanding topologies.	Acceptable only in cost-driven, non-safety-critical applications where gate protection and avalanche stress are absent.

Compared with STP5NK50Z, STD5NK50ZT4 offers superior thermal integration via DPAK's low-profile SMT footprint and PCB copper thermal spreading, while FQP5N50 lacks documented avalanche robustness and gate protection - making STD5NK50ZT4 the only choice for certified, high-reliability offline power stages.

Availability

STD5NK50ZT4 is available at Aetrix Electronics and suitable for AC-DC adapters, industrial PFC modules, and LED driver power stages requiring stable component supply across production lifecycles.

Supply support for STD5NK50ZT4 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, and analog/mixed-signal ICs for industrial, automotive, and consumer markets.

STD5NK50ZT4 belongs to ST's SuperMESH™ Power MOSFET product line, engineered specifically for high-efficiency, high-reliability offline switching applications where avalanche ruggedness, low gate charge, and integrated protection are mandatory.

FAQ

Is STD5NK50ZT4 pin-compatible with other DPAK MOSFETs like IRF640 or FQP5N50?

No. STD5NK50ZT4 uses standard DPAK pinout (G-D-S), but electrical characteristics differ significantly: IRF640 has 180 nC Q_g and no Zener protection; FQP5N50 lacks avalanche rating. Direct substitution requires gate drive and thermal redesign due to 20 nC vs. 71 nC (IRF640) and missing ESD/avalanche safeguards.

What is the maximum PCB copper area required to achieve R_thj-pcb = 50 °C/W?

A 1-inch² (645 mm²) FR-4 board with 2 oz copper, centered under the DPAK tab, achieves R_thj-pcb = 50 °C/W per DS2834 Table 2. Larger copper pours improve thermal performance, but minimum recommended pad dimensions are 5.2 mm × 6.5 mm (per Figure 24) to ensure solder joint integrity and thermal transfer.

Does STD5NK50ZT4 support 10 V gate drive, or is 15 V required for full R_DS(on)?

STD5NK50ZT4 is fully characterized at V_GS = 10 V (R_DS(on) = 1.22 Ω typ.), and its gate threshold voltage (V_GS(th)) ranges from 3.0 to 4.5 V. It operates reliably with standard 10 V logic-level drivers (e.g., TL494, UC3845) - no 15 V bias is needed for rated conduction performance.

Can STD5NK50ZT4 replace STP5NK50Z in an existing TO-220 design without layout changes?

No. STD5NK50ZT4 is a surface-mount DPAK device; STP5NK50Z is through-hole TO-220. Physical footprint, thermal interface, and soldering method are incompatible. Migration requires PCB redesign, gate drive impedance adjustment (due to lower Q_g), and verification of dv/dt-induced noise immunity in the new layout.

STD5NK50Z-1 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: SuperMESH™

Package/Case:: TO-251-3 Short Leads, IPAK, TO-251AA

Packaging:: Tube

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 500 V

Current - Continuous Drain (Id) @ 25°C:: 4.4A (Tc)

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

Rds On (Max) @ Id, Vgs:: 1.5Ohm @ 2.2A, 10V

Vgs(th) (Max) @ Id:: 4.5V @ 50µA

Gate Charge (Qg) (Max) @ Vgs:: 28 nC @ 10 V

Vgs (Max):: ±30V

Input Capacitance (Ciss) (Max) @ Vds:: 535 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 70W (Tc)

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: IPAK

STD5NK50Z-1 FAQ

1.How can I place an order for STD5NK50Z-1 through Aetrix?

Please submit a Request for Quotation (RFQ) for STD5NK50Z-1 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 STD5NK50Z-1 reliable?

The price and inventory of STD5NK50Z-1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STD5NK50Z-1 is usually 5 days.

3.What payment methods are accepted for STD5NK50Z-1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STD5NK50Z-1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STD5NK50Z-1?

STD5NK50Z-1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STD5NK50Z-1 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 STD5NK50Z-1?

For technical support, including STD5NK50Z-1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STD5NK50Z-1 requirements.

6.How does Aetrix verify that STD5NK50Z-1 is sourced from the original manufacturer or authorized distributors?

All STD5NK50Z-1 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 STD5NK50Z-1 meets industry standards.

7.What is the process for return or replacement of STD5NK50Z-1?

All STD5NK50Z-1 units undergo pre-shipment inspection (PSI). If there is an issue with STD5NK50Z-1, 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 STD5NK50Z-1 part is unused and in its original packaging.

Return procedure for STD5NK50Z-1:

1.Submit a request within 90 days.

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

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