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

STMicroelectronics STI5N52U

Name: STI5N52U
Brand: STMicroelectronics
SKU: STI5N52U
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STI5N52U

Manufacturer:: STMicroelectronics

Category:: FETs, MOSFETs

Package:: TO-262-3 Long Leads, I2PAK, TO-262AA

Datasheet:: STI5N52U.pdf

Description:: MOSFET N-CH 525V 4.4A I2PAK

Quantity:: RFQ Add To RFQ list

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Inventory:3,006

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Product details

Overview

STI5N52U from STMicroelectronics is an N-channel 525 V, 1.25 Ω typ. R_DS(on), 4.4 A UltraFASTmesh™ Power MOSFET in I²PAK (TO-262) package, featuring 55 ns trr, 20 V/ns dv/dt capability, and integrated gate Zener protection. It serves as a high-voltage switching device in offline SMPS primary-side circuits.

For engineers reviewing the STI5N52U datasheet, STI5N52U pinout, STI5N52U application, or STI5N52U equivalent, key selection criteria include avalanche energy rating (170 mJ), low Crss (13.4 pF), fast turn-off (23.1 ns td(off)), and thermal resistance (1.78 °C/W R_thj-case).

Technical Context

This MOSFET employs UltraFASTmesh™ silicon technology to simultaneously optimize conduction loss (R_DS(on) = 1.25 Ω typ.), switching speed (trr = 55 ns at TJ = 25 °C), and ruggedness (EAS = 170 mJ, dv/dt = 20 V/ns). Its integrated back-to-back gate Zener diodes provide ±30 V V_GS protection without external components.

The device features a fast-recovery body diode with 95 nC Q_rr and 3.5 A I_RRM at 25 °C, enabling efficient hard-switching in flyback and resonant converters. Thermal design is supported by low junction-to-case resistance (1.78 °C/W) and rated for continuous operation up to T_J = 150 °C.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DSS	525 V - supports 380 V DC bus with 30% margin for surge and ringing in offline power supplies
R_DS(on) typ.	1.25 Ω - enables <4.4 A continuous drain current with ≤6.1 W conduction loss at 25 °C case
trr	55 ns - minimizes switching loss and EMI in 65–100 kHz flyback topologies
Q_g	16.9 nC - determines gate drive strength requirement; compatible with standard 1 A peak drivers
EAS	170 mJ - withstands unclamped inductive switching events without failure under defined SOA
dv/dt	20 V/ns - ensures robust immunity to parasitic turn-on in high-noise, high-dV/dt environments
R_thj-case	1.78 °C/W - allows 70 W dissipation with ≤125 °C temperature rise above 25 °C heatsink

Pinout & Package

I²PAK (TO-262) package with isolated tab (drain-connected), 3-pin through-hole outline, 10 mm × 14 mm footprint, and 4.6 mm height. Tab is electrically connected to drain for direct heatsinking.

Pin/Terminal	Circuit Role	Design Meaning
1 (G)	Gate	Control terminal; accepts 10 V logic-level drive; protected by integrated ±30 V Zener
2 (D) / Tab	Drain	Main high-side power terminal; electrically tied to metal tab for low-inductance heatsinking
3 (S)	Source	Power return path and reference for gate drive; forms common node with driver ground

Key Features

Feature	Design Value
UltraFASTmesh™ silicon process	Enables simultaneous optimization of R_DS(on), Q_g, and trr - not achievable with planar or trench-only processes
Integrated gate Zener diodes	Eliminates need for external gate protection clamps in cost-sensitive consumer power supplies
Enhanced body diode recovery	Reduces Q_rr-related switching loss and voltage overshoot during hard commutation
High dv/dt immunity	Prevents false triggering in high-side configurations with steep phase-node transitions

Applications

AC-DC Adapter Primary Switch

Flyback SMPS for LED Drivers

Use Scenario: 12–24 W universal-input (85–265 V_AC) adapter powering USB-C devices.

IC Role / Device Role / Timing Role: Main high-side switching element in discontinuous conduction mode (DCM) flyback converter operating at 65 kHz.

Use Value: Low R_DS(on) reduces conduction loss at light load; fast trr minimizes dead-time loss and improves efficiency >85% at full load.

Use Scenario: Constant-voltage LED driver for commercial downlights with 300–400 V_DC bus.

IC Role / Device Role / Timing Role: Primary-side switch managing energy transfer across isolation barrier in quasi-resonant (QR) flyback.

Use Value: 525 V rating accommodates 400 V_DC bus + 30% transient margin; 170 mJ EAS handles leakage inductance spikes.

Industrial AC-DC Power Supply

Offline Charger for Small Appliances

Use Scenario: 65 W open-frame PSU for PLC I/O modules requiring wide input range and long lifetime.

IC Role / Device Role / Timing Role: Primary switch in active-clamp forward topology with 100 kHz switching frequency.

Use Value: 20 V/ns dv/dt rating prevents spurious turn-on during high dV/dt transitions across transformer primary.

Use Scenario: 18 W wall-mounted charger for cordless vacuum accessories with no external fuse.

IC Role / Device Role / Timing Role: Self-protected switching transistor in low-cost, non-isolated buck-derived topology.

Use Value: Integrated gate Zener eliminates discrete clamp diode, reducing BOM count and PCB area by 2 components.

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
STP5N52FD	Same V_DSS (520 V), higher R_DS(on) (1.8 Ω max), lower Q_g (12.5 nC), D²PAK package	Higher conduction loss but better thermal spread in surface-mount layouts	Select when board space favors SMD and thermal interface uses large copper pour
IPP50R1K0CP	500 V rating, 1.0 Ω R_DS(on), 17.5 nC Q_g, CoolMOS™ P7 technology, TO-220FP	Lower on-resistance but reduced voltage margin; optimized for 380 V DC bus only	Select for higher efficiency at 380 V DC where 525 V headroom is unnecessary

Compared with STP5N52FD and IPP50R1K0CP, STI5N52U delivers superior voltage margin and dv/dt immunity for universal-input designs, while its I²PAK package offers lower thermal resistance than TO-220FP and simpler mounting than D²PAK in through-hole production.

Availability

STI5N52U is available at Aetrix Electronics and suitable for AC-DC adapters, LED driver power stages, and industrial offline SMPS requiring stable component supply and legacy design continuity.

Supply support for STI5N52U 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, designing and manufacturing analog, MCU, power, and sensor solutions for automotive, industrial, and consumer markets.

STI5N52U belongs to the UltraFASTmesh™ Power MOSFET product line, engineered specifically for high-efficiency, high-reliability offline switching applications where ruggedness and fast recovery are critical.

FAQ

Is STI5N52U recommended for new designs?

No. STMicroelectronics explicitly states "not recommended for new design" in the July 2014 datasheet (DocID026740 Rev 1). It remains in production for legacy program support but lacks roadmap extension. New designs should evaluate ST's latest UltraFASTmesh™-II or MDmesh™ DM6 devices with improved R_DS(on)/Q_g ratios and enhanced reliability.

What is the maximum safe operating temperature for continuous operation?

The STI5N52U has a maximum operating junction temperature (T_J) of 150 °C. With R_thj-case = 1.78 °C/W and P_TOT = 70 W at T_C = 25 °C, sustained operation requires heatsinking that maintains case temperature ≤ 75 °C to keep T_J within limit under full load.

Does STI5N52U require external gate protection?

No. The device integrates back-to-back Zener diodes between gate and source, rated for ±30 V breakdown (V_(BR)GSO). This provides sufficient protection against ESD (2800 V HBM) and transient overvoltage without external components-confirmed in Section 5 of the datasheet.

Can STI5N52U replace STP5N52U in existing boards?

Yes, with verification. Both share identical V_DSS (525 V), R_DS(on) (1.5 Ω max), and I_D (4.4 A), and use the same I²PAK package and pinout. However, STI5N52U adds UltraFASTmesh™-specific improvements: lower trr (55 ns vs. 100+ ns), higher dv/dt (20 V/ns), and integrated Zener protection-requiring validation of gate drive timing and snubber design.

STI5N52U Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: UltraFASTmesh™

Package/Case:: TO-262-3 Long Leads, I2PAK, TO-262AA

Packaging:: Tube

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 525 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:: 16.9 nC @ 10 V

Vgs (Max):: ±30V

Input Capacitance (Ciss) (Max) @ Vds:: 529 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:: I2PAK

STI5N52U FAQ

1.How can I place an order for STI5N52U through Aetrix?

Please submit a Request for Quotation (RFQ) for STI5N52U 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 STI5N52U reliable?

The price and inventory of STI5N52U are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STI5N52U is usually 5 days.

3.What payment methods are accepted for STI5N52U?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STI5N52U transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STI5N52U?

STI5N52U orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STI5N52U 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 STI5N52U?

For technical support, including STI5N52U datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STI5N52U requirements.

6.How does Aetrix verify that STI5N52U is sourced from the original manufacturer or authorized distributors?

All STI5N52U 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 STI5N52U meets industry standards.

7.What is the process for return or replacement of STI5N52U?

All STI5N52U units undergo pre-shipment inspection (PSI). If there is an issue with STI5N52U, 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 STI5N52U part is unused and in its original packaging.

Return procedure for STI5N52U:

1.Submit a request within 90 days.

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

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