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

Infineon Technologies IRFR3103

Name: IRFR3103
Brand: Infineon Technologies
SKU: IRFR3103
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: IRFR3103

Manufacturer:: Infineon Technologies

Category:: FETs, MOSFETs

Package:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Datasheet:: IRFR3103.pdf

Description:: MOSFET N-CH 400V 1.7A DPAK

Quantity:: RFQ Add To RFQ list

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Inventory:5,198

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Product details

Overview

IRFR3103 from Infineon Technologies is a N-channel enhancement-mode MOSFET rated for 400 V V_DS, 1.7 A continuous drain current at T_C = 25°C, and R_DS(on) ≤ 1.8 Ω at V_GS = 10 V. It operates in hard-switched flyback and offline SMPS primary-side switching applications with low gate charge (Q_g = 12 nC) and fast turn-on/turn-off times.

For engineers reviewing the IRFR3103 datasheet, IRFR3103 pinout, IRFR3103 application, or IRFR3103 equivalent, key selection criteria include its 400 V blocking voltage, DPAK (TO-252) package thermal performance, R_DS(on) stability over temperature, and suitability for 20–100 kHz isolated DC-DC converters.

Technical Context

This MOSFET employs planar stripe silicon technology with optimized cell pitch and field plate design to achieve high voltage ruggedness and controlled avalanche capability (E_AS = 110 mJ). Its gate threshold voltage (V_GS(th)) ranges from 2.0 V to 4.0 V, enabling reliable drive from 5 V or 10 V controllers.

The device features a fully characterized safe operating area (SOA) up to 10 ms at 25°C, supports unclamped inductive switching, and exhibits low reverse recovery charge (Q_rr = 25 nC) when used with external freewheeling diodes in discontinuous conduction mode topologies.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	400 V - Supports mains-referenced primary switches in universal-input offline SMPS up to 265 V_AC.
I_D (continuous)	1.7 A @ T_C = 25°C - Sufficient for <15 W flyback adapters with derating to 1.1 A at 100°C case temperature.
R_DS(on)	≤1.8 Ω @ V_GS = 10 V - Enables <3 W conduction loss at 1.7 A, critical for efficiency in compact adapters.
Q_g	12 nC - Reduces gate drive power and enables use with low-current PWM controllers like UC3842/UC3843.
E_AS	110 mJ - Confirmed single-pulse avalanche energy rating ensures robustness during output short-circuit or overload events.
t_f	25 ns - Fast fall time minimizes switching loss during hard-switched transitions at ≤100 kHz.

Pinout & Package

Package: DPAK (TO-252), surface-mount, single-drain tab configuration with exposed drain pad for thermal dissipation.

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (Source)	Source terminal	Reference node for gate drive; connects to primary ground in flyback circuits.
Pin 2 (Gate)	Control input	High-impedance MOSFET gate requiring <12 nC charge for full enhancement.
Pin 3 (Drain)	High-voltage switch node	Connected to transformer primary and bulk capacitor; carries full AC line-referenced voltage swing.

Key Features

Feature	Design Value
100% avalanche tested	Each unit validated to withstand 110 mJ single-pulse avalanche without parameter shift.
Low gate charge	Q_g = 12 nC enables efficient drive from low-power PWM ICs without external buffer stages.
Enhanced SOA	Rated for 1.7 A at 400 V for 10 ms - supports temporary overloads without thermal runaway.
Lead-free and RoHS compliant	Meets EU Directive 2011/65/EU; compatible with standard Pb-free reflow profiles (peak 260°C).

Applications

AC-DC Adapter Primary Switch

Flyback Converter Main Switch

Use Scenario: 12 V/1 A universal-input wall adapter powering IoT sensors.

IC Role / Device Role / Timing Role: Primary-side high-voltage switch synchronizing with transformer reset and PWM controller timing.

Use Value: 400 V rating accommodates 265 V_AC input surges; 1.8 Ω R_DS(on) limits conduction loss to <3 W at full load.

Use Scenario: Isolated 5 V/2 A auxiliary supply in industrial PLC power stage.

IC Role / Device Role / Timing Role: Hard-switched main transistor controlling energy transfer during ON-time of UC3844-based controller.

Use Value: 12 nC Q_g reduces gate driver stress and allows direct connection to controller's 200 mA peak output.

LED Driver Primary Switch

Offline SMPS Standby Supply

Use Scenario: Constant-voltage LED driver for commercial signage operating from 90–305 V_AC.

IC Role / Device Role / Timing Role: Primary-side switching element in quasi-resonant flyback topology with valley-switching control.

Use Value: 25 ns t_f and low Q_rr minimize switching loss during high-frequency burst-mode operation.

Use Scenario: 3.3 V/100 mA standby rail in multi-output ATX power supply.

IC Role / Device Role / Timing Role: Low-duty-cycle primary switch activated only during system sleep states.

Use Value: Confirmed 110 mJ E_AS ensures reliability during repeated cold-start inrush and no-load transients.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
STP3NK40ZFP	R_DS(on) = 2.2 Ω (higher), Q_g = 14 nC (higher), same 400 V rating and TO-220FP package.	Lower efficiency at full load due to higher conduction loss; requires larger heatsink in thermally constrained layouts.	Prefer IRFR3103 where PCB space and thermal resistance demand lower R_DS(on) and surface-mount assembly.
FQP4N40	R_DS(on) = 2.5 Ω, Q_g = 16 nC, TO-220 package - no exposed drain pad, higher thermal resistance.	Not suitable for high-density SMT designs; limited SOA at elevated temperatures.	Select IRFR3103 for automated assembly, improved thermal coupling via DPAK drain pad, and tighter SOA margin.

Compared with STP3NK40ZFP and FQP4N40, the IRFR3103 delivers lower conduction loss and superior thermal performance in SMT-based offline converters, while maintaining identical voltage rating and avalanche robustness - making it optimal for space-constrained, efficiency-sensitive 10–20 W SMPS designs.

Availability

IRFR3103 is available at Aetrix Electronics and suitable for AC-DC adapters, flyback converters, LED drivers, and offline SMPS standby supplies requiring stable component supply and long-term manufacturability.

Supply support for IRFR3103 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

Infineon Technologies is a German semiconductor manufacturer specializing in power management, automotive microcontrollers, and industrial gate drivers.

The StrongIRFET™ product line targets cost-sensitive, high-reliability power conversion applications - specifically engineered for ruggedized primary-side switching in universal-input offline SMPS.

FAQ

What is the maximum junction temperature for continuous operation?

The IRFR3103 has a maximum rated junction temperature of 150°C. Derated operation is required above T_C = 25°C per the SOA curve; at T_C = 100°C, continuous I_D drops to 1.1 A. Thermal design must ensure θ_JA ≤ 62°C/W on 1-in² 2-oz copper with minimal airflow.

Is the IRFR3103 suitable for zero-voltage switching (ZVS) topologies?

No - the IRFR3103 is optimized for hard-switched operation. Its body diode reverse recovery characteristics (Q_rr = 25 nC, t_rr = 55 ns) are not tuned for ZVS or resonant LLC operation, where ultra-low Q_rr and soft recovery are mandatory.

Does the DPAK package require solder paste stencil optimization?

Yes - the exposed drain pad must be soldered with ≥70% copper fill and thermal vias (≥4×0.3 mm) to inner ground planes. IPC-7351B footprint with 2.5 mm × 6.5 mm pad and 0.3 mm solder mask opening is recommended to ensure mechanical reliability and thermal performance.

Can the IRFR3103 replace the IRFRC20 in existing designs?

Yes - both share 400 V rating and DPAK package, but IRFR3103 offers 1.8 Ω vs. 2.2 Ω R_DS(on) and 12 nC vs. 14 nC Q_g. Gate drive compatibility is maintained; layout changes are unnecessary, though efficiency improves by ~0.8% at full load in typical 12 V/1 A adapters.

IRFR3103 Specifications

Product attributes: Attribute value

Manufacturer:: Infineon Technologies

Series:: HEXFET®

Package/Case:: TO-252-3, DPAK (2 Leads + Tab), SC-63

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:: 1.7A (Ta)

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

Rds On (Max) @ Id, Vgs:: 3.6Ohm @ 1A, 10V

Vgs(th) (Max) @ Id:: 4V @ 250µA

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

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 170 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 2.5W (Ta), 25W (Tc)

Operating Temperature:: -

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: TO-252AA (DPAK)

IRFR3103 FAQ

1.How can I place an order for IRFR3103 through Aetrix?

Please submit a Request for Quotation (RFQ) for IRFR3103 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 IRFR3103 reliable?

The price and inventory of IRFR3103 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IRFR3103 is usually 5 days.

3.What payment methods are accepted for IRFR3103?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IRFR3103 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for IRFR3103?

IRFR3103 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your IRFR3103 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 IRFR3103?

For technical support, including IRFR3103 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IRFR3103 requirements.

6.How does Aetrix verify that IRFR3103 is sourced from the original manufacturer or authorized distributors?

All IRFR3103 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 IRFR3103 meets industry standards.

7.What is the process for return or replacement of IRFR3103?

All IRFR3103 units undergo pre-shipment inspection (PSI). If there is an issue with IRFR3103, 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 IRFR3103 part is unused and in its original packaging.

Return procedure for IRFR3103:

1.Submit a request within 90 days.

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

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