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

STMicroelectronics STULED524

Name: STULED524
Brand: STMicroelectronics
SKU: STULED524
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STULED524

Manufacturer:: STMicroelectronics

Category:: FETs, MOSFETs

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

Datasheet:: STULED524.pdf

Description:: MOSFET N-CH 525V 4A IPAK

Quantity:: RFQ Add To RFQ list

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Inventory:8,605

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Product details

Overview

STULED524 from STMicroelectronics is an N-channel 525 V, 2.1 Ω typ. (at V_GS = 10 V, I_D = 2.2 A), 4.0 A Power MOSFET in IPAK (TO-251) package, featuring Zener-protected gate, 100% avalanche tested, and optimized for LED lighting flyback and buck-boost converters.

For engineers reviewing the STULED524 datasheet, STULED524 pinout, STULED524 application, or STULED524 equivalent, key selection criteria include its 525 V V_DS, low R_DS(on), high dv/dt capability (12 V/ns), improved diode reverse recovery (t_rr = 173 ns at T_J = 25 °C), and integrated gate-source Zener protection (BVGSO = 30 V).

Technical Context

This MOSFET employs a planar stripe silicon process with built-in back-to-back Zener diodes across gate-source to suppress transients and enhance ESD robustness without external components. Its low output capacitance (C_oss eq. = 22 pF) and fast switching (t_d(on) = 8 ns, t_f = 14 ns) support high-frequency operation in isolated LED drivers.

The device operates with a gate threshold voltage of 3.0–4.5 V and exhibits stable on-resistance over temperature (R_DS(on) normalized to 1.3× at T_J = 150 °C). Thermal resistance junction-case is 2.78 °C/W, enabling 45 W total dissipation at T_C = 25 °C in the IPAK package.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	525 V - Withstands peak line voltages up to 370 VAC in universal-input LED drivers without derating.
R_DS(on) max	2.6 Ω - Ensures <10.4 W conduction loss at 4.0 A DC, critical for thermal management in enclosed luminaires.
I_D (T_C = 25 °C)	4.0 A - Supports continuous LED string currents up to 4 A in single-stage flyback topologies.
E_AS	110 mJ - Enables reliable unclamped inductive switching in flyback snubberless designs.
dv/dt capability	12 V/ns - Prevents spurious turn-on during high-slew-rate voltage transients in high-noise LED driver environments.
t_rr (I_SD = 2.5 A)	173 ns - Reduces switching losses and EMI in secondary-side synchronous rectification or freewheeling paths.
BVGSO	30 V - Integrated gate-source Zener clamps gate voltage during surge events, eliminating need for external TVS.

Pinout & Package

STULED524 is housed in an IPAK (TO-251) package with three terminals: Drain (Tab), Gate (Pin 1), and Source (Pin 3). The metal tab is electrically connected to the Drain and serves as the primary thermal path. Mounting requires isolation from heatsink unless drain-referenced layout is intended.

Pin/Terminal	Circuit Role	Design Meaning
Tab (Drain)	High-voltage power switch node	Connected directly to primary-side high-voltage rail; must be thermally coupled to heatsink with electrical isolation if needed.
Pin 1 (G)	Gate control input	Receives PWM drive signal; low gate charge (Q_g = 12 nC) enables efficient driving with standard gate drivers.
Pin 3 (S)	Source return path	Reference node for gate drive and current sensing; tied to primary ground in flyback configurations.

Key Features

Feature	Design Value
100% avalanche tested	Guarantees ruggedness under unclamped inductive switching stress (E_AS = 110 mJ), reducing need for snubbers in cost-sensitive LED drivers.
Zener-protected gate	Integrated 30 V gate-source Zener eliminates external protection components, saving PCB space and BOM cost in compact LED modules.
Extremely high dv/dt capability	12 V/ns rating prevents false triggering during fast voltage transitions common in discontinuous conduction mode (DCM) flyback operation.
Improved diode reverse recovery	t_rr = 173 ns and Q_rr = 778 µC reduce switching losses and EMI generation when used as freewheeling or synchronous rectifier devices.
Very low intrinsic capacitance	C_iss = 340 pF, C_oss eq. = 22 pF - minimizes capacitive losses and improves efficiency above 100 kHz switching frequencies.

Applications

LED Driver – Flyback

LED Driver – Buck-Boost

Use Scenario: Universal-input (90–264 VAC), 20–40 W isolated LED driver for commercial downlights.

IC Role / Device Role: Primary-side power switch in DCM flyback topology, operating at 65 kHz with ZVS-assisted turn-on.

Use Value: 525 V rating allows direct connection to rectified mains without voltage divider; low R_DS(on) maintains >88% efficiency at full load.

Use Scenario: Non-isolated, constant-current LED driver for streetlight modules with wide input range (12–48 VDC).

IC Role / Device Role: High-side switch in buck-boost regulator controlling 3–10 A LED strings.

Use Value: Avalanche ruggedness absorbs inductive kickback during current regulation transients; Zener gate protection avoids failure during bus voltage surges.

Smart Lighting Control

Dimmable AC/DC LED Module

Use Scenario: DALI-enabled LED driver with integrated microcontroller and analog dimming interface.

IC Role / Device Role: Main switching element handling both power conversion and rapid PWM dimming response.

Use Value: Fast switching (t_f = 14 ns) supports high-frequency dimming (>1 kHz) without audible noise; low Q_gd/Q_gs ratio ensures clean gate drive waveform.

Use Scenario: TRAIC-dimmable LED module for residential retrofit lamps (E27, GU10).

IC Role / Device Role: Leading-edge phase-cut compatible switch in quasi-resonant flyback with valley-switching control.

Use Value: High dv/dt immunity prevents misfiring during TRIAC commutation; improved diode recovery reduces flicker and EMI during dimming transitions.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
STP5NK50ZFP	500 V V_DS, 1.2 Ω R_DS(on), TO-220FP package, no integrated Zener	Limited to ≤265 VAC inputs; requires external gate protection and higher gate drive current due to larger Q_g (27 nC)	Choose only if lower R_DS(on) is prioritized and board space allows external Zener + RC filter.
FQP5N50C	500 V V_DS, 1.4 Ω R_DS(on), TO-220 package, no avalanche rating or Zener	No guaranteed avalanche energy or gate protection; unsuitable for surge-prone lighting environments	Acceptable only in low-cost, non-certified indoor lamps with regulated DC input and minimal transient exposure.

Compared with STP5NK50ZFP and FQP5N50C, STULED524 delivers superior system-level reliability in AC-coupled LED drivers through its 525 V rating, integrated Zener, and 110 mJ avalanche energy-enabling simpler, smaller, and more robust designs without sacrificing efficiency.

Availability

STULED524 is available at Aetrix Electronics and suitable for LED lighting flyback converters, buck-boost drivers, and dimmable AC/DC modules requiring stable component supply, long-term lifecycle assurance, and consistent parametric performance across production batches.

Supply support for STULED524 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, power, MCU, and sensor solutions for industrial, automotive, and consumer markets.

STULED524 belongs to ST's STD/STF/STP/STU LED Power MOSFET family, engineered specifically for high-efficiency, high-reliability LED lighting power conversion with emphasis on ruggedness, low conduction loss, and integration of protection features.

FAQ

Is STULED524 pin-compatible with other ST LED MOSFETs like STDLED524?

No. STULED524 uses the IPAK (TO-251) package with Drain on the tab, Gate on Pin 1, and Source on Pin 3. STDLED524 is in DPAK (TO-252) with identical pinout orientation but different mechanical footprint and thermal pad layout. PCB layout and heatsinking must be redesigned for IPAK.

What is the maximum recommended gate resistor value for STULED524 in a 65 kHz flyback design?

Based on Q_g = 12 nC and typical gate driver output impedance, a 10 Ω series gate resistor provides optimal trade-off between switching speed (t_f ≈ 14 ns) and EMI suppression. Values above 22 Ω increase switching losses significantly; below 4.7 Ω risk ringing without proper PCB layout control.

Does STULED524 require external gate protection despite its integrated Zener diode?

No external Zener is required for gate-source voltage clamping, as BVGSO = 30 V is fully rated and tested. However, a small RC snubber (e.g., 100 Ω + 100 pF) between gate and source is recommended near the device to damp high-frequency oscillation caused by PCB trace inductance.

Can STULED524 be used in linear-regulation mode for analog dimming?

No. STULED524 is not characterized or qualified for linear (ohmic) operation. Its Safe Operating Area (SOA) curve shows limited DC capability at V_DS > 100 V, and sustained linear use risks thermal runaway. It must operate in switched mode only, per datasheet SOA limits.

STULED524 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

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

Packaging:: Tube

Product Status:: Active

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 525 V

Current - Continuous Drain (Id) @ 25°C:: 4A (Tc)

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

Rds On (Max) @ Id, Vgs:: 2.6Ohm @ 2.2A, 10V

Vgs(th) (Max) @ Id:: 4.5V @ 50µA

Gate Charge (Qg) (Max) @ Vgs:: 12 nC @ 10 V

Vgs (Max):: ±30V

Input Capacitance (Ciss) (Max) @ Vds:: 340 pF @ 100 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-251 (IPAK)

STULED524 FAQ

1.How can I place an order for STULED524 through Aetrix?

Please submit a Request for Quotation (RFQ) for STULED524 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 STULED524 reliable?

The price and inventory of STULED524 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STULED524 is usually 5 days.

3.What payment methods are accepted for STULED524?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STULED524 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STULED524?

STULED524 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STULED524 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 STULED524?

For technical support, including STULED524 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STULED524 requirements.

6.How does Aetrix verify that STULED524 is sourced from the original manufacturer or authorized distributors?

All STULED524 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 STULED524 meets industry standards.

7.What is the process for return or replacement of STULED524?

All STULED524 units undergo pre-shipment inspection (PSI). If there is an issue with STULED524, 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 STULED524 part is unused and in its original packaging.

Return procedure for STULED524:

1.Submit a request within 90 days.

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

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