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

Infineon Technologies IRFL4105

Name: IRFL4105
Brand: Infineon Technologies
SKU: IRFL4105
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: IRFL4105

Manufacturer:: Infineon Technologies

Category:: FETs, MOSFETs

Package:: TO-261-4, TO-261AA

Datasheet:: IRFL4105.pdf

Description:: MOSFET N-CH 55V 3.7A SOT223

Quantity:: RFQ Add To RFQ list

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Product details

Overview

IRFL4105 from International Rectifier is a 55V, 3.7A N-channel enhancement-mode power MOSFET in SOT-223 package, featuring 0.045Ω R_DS(on) at V_GS = 10V, 100% avalanche-rated operation, and fast switching (t_r = 12ns, t_f = 12ns). It serves as a high-efficiency low-side switch in DC-DC converters and motor control stages.

For engineers reviewing the IRFL4105 datasheet, IRFL4105 pinout, IRFL4105 application, or IRFL4105 equivalent, key selection criteria include its thermal resistance (R_θJA = 90°C/W on FR-4), body diode recovery performance (t_rr = 55–82ns), unclamped inductive switching capability (E_AS = 110mJ), and logic-level gate drive compatibility (V_GS(th) = 2.0–4.0V).

Technical Context

This HEXFET device uses fifth-generation silicon processing to achieve ultra-low on-resistance per die area while maintaining ruggedness against repetitive and single-pulse avalanche stress. Its SOA is defined up to 10ms pulses at T_J = 25°C with R_DS(on)-limited conduction boundary.

The integrated body diode supports synchronous rectification and freewheeling functions, with V_SD = 1.3V at I_S = 3.7A and controlled reverse recovery (Q_rr = 120–170nC, di/dt = 100A/µs). Gate charge parameters (Q_g = 23–35nC, Q_gd = 9.8–15nC) enable efficient 200kHz–500kHz switching in compact SMPS designs.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DSS	55V - Maximum blocking voltage before avalanche onset; defines safe operating range in 24V/48V bus applications.
R_DS(on)	0.045Ω @ V_GS = 10V, I_D = 3.7A - Enables <165mW conduction loss at full rated current, critical for thermally constrained SMT layouts.
I_D (continuous)	3.7A @ T_A = 25°C - Validated continuous current rating on standard FR-4 PCB with minimum footprint; derates to 3.0A at 70°C ambient.
E_AS	110mJ - Single-pulse avalanche energy rating confirms robustness during inductive turn-off transients without external snubbers.
t_r/t_f	12ns/12ns - Fast edge rates reduce switching losses and EMI generation in high-frequency buck regulators and half-bridge drivers.
Q_g	23–35nC - Total gate charge determines driver strength requirement; compatible with low-power gate drivers like IR2110 or TC4427.
R_θJA	90°C/W (FR-4) - Thermal resistance enables 1.0W dissipation without heatsink; improves reliability over SOT-23 alternatives.

Pinout & Package

SOT-223 (TO-261AA) surface-mount package with exposed drain tab for enhanced thermal conduction. The molded plastic body supports vapor-phase, infrared, and wave soldering; pick-and-place compatible with standard SOT feeders.

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (Source)	Source terminal (S)	Common return path for load current; electrically tied to substrate backside in SOT-223 construction.
Pin 2 (Gate)	Control input (G)	High-impedance MOS gate requiring <100nA leakage; sensitive to ESD but tolerant of ±20V transient overvoltage.
Pin 3 (Drain)	Power output (D)	Internally connected to large copper tab; primary thermal path to PCB copper pour; must be routed with low-inductance layout.
Tab (Drain)	Drain terminal (D)	Exposed metal pad serving as second drain connection and main heatsink interface; requires solder mask opening and thermal via array.

Key Features

Feature	Design Value
Fifth-generation HEXFET process	Delivers 0.045Ω R_DS(on) in SOT-223 - 35% lower than prior-gen equivalents at same current rating.
100% avalanche rated	Guarantees operation under unclamped inductive switching up to 110mJ without parameter shift or failure.
Enhanced thermal performance	90°C/W R_θJA on FR-4 - 40% improvement vs. comparable SOT-23 MOSFETs, enabling higher power density.
Fast body diode recovery	t_rr = 55–82ns with Q_rr = 120–170nC - Reduces cross-conduction loss in synchronous buck topologies.
Logic-level gate threshold	V_GS(th) = 2.0–4.0V - Ensures full enhancement with 3.3V or 5V microcontroller GPIO, eliminating level-shifter need.

Applications

DC-DC Buck Converter

Brushed DC Motor Driver

Use Scenario: Step-down regulation from 24V to 5V/3.3V in industrial IoT nodes with space-constrained PCBs.

IC Role / Device Role / Timing Role: Low-side synchronous rectifier replacing Schottky diode to improve efficiency by >3% at 2A load.

Use Value: 0.045Ω R_DS(on) cuts conduction loss to 180mW, reducing thermal rise and enabling fanless enclosure design.

Use Scenario: H-bridge half-bridge stage driving 12V, 2A brushed motors in portable medical pumps.

IC Role / Device Role / Timing Role: High-side or low-side switch controlling motor direction and PWM speed modulation at 20kHz.

Use Value: Avalanche rating absorbs inductive kickback during rapid PWM transitions, eliminating need for external TVS clamps.

LED Constant-Current Driver

Load Switch for 24V Industrial Sensors

Use Scenario: Precision current sink for 350mA white LED strings in emergency lighting systems.

IC Role / Device Role / Timing Role: Linear or PWM-controlled pass element regulating LED current via source-follower feedback.

Use Value: Low R_DS(on) minimizes voltage headroom requirement, allowing operation down to 2.5V supply margin above LED V_F.

Use Scenario: Controlled 24V power delivery to fieldbus sensors with inrush current limiting and fault protection.

IC Role / Device Role / Timing Role: High-side load switch enabling hot-swap capability and remote ON/OFF control via MCU GPIO.

Use Value: 55V V_DSS provides 2× safety margin over 24V rail; R_DS(on) stability over temperature ensures consistent current limiting.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
DMN3020LSD-13	R_DS(on) = 0.032Ω @ 4.5V, but V_DSS = 30V only	Not suitable for 48V bus or 55V surge environments	Select only for 3.3V/5V logic-driven 24V systems where lower gate threshold is prioritized over voltage margin.
SI2305DS-T1-E3	V_DSS = 30V, R_DS(on) = 0.042Ω @ 4.5V, SOT-23 package	Thermal limit capped at 0.7W due to smaller package; no avalanche rating	Acceptable for low-duty-cycle signal switching but not for continuous 3.7A power switching or inductive loads.

Compared with DMN3020LSD-13 and SI2305DS-T1-E3, the IRFL4105 uniquely balances 55V rating, 0.045Ω on-resistance, full avalanche ruggedness, and SOT-223 thermal capability-making it the only option among the three qualified for 24V/48V industrial power switching with sustained 3.7A current.

Availability

IRFL4105 is available at Aetrix Electronics and suitable for DC-DC buck converters, brushed DC motor drivers, LED constant-current drivers, and 24V industrial load switches requiring stable component supply across production lifecycles.

Supply support for IRFL4105 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

International Rectifier (now part of Infineon Technologies) was a pioneer in power semiconductor innovation, specializing in high-efficiency MOSFETs, IGBTs, and driver ICs for industrial, automotive, and computing markets.

The HEXFET® product line was engineered specifically for high-reliability power switching applications demanding low conduction loss, fast switching, and intrinsic avalanche tolerance-targeting SMPS, motor drives, and battery-powered systems.

FAQ

Is IRFL4105 suitable for 3.3V microcontroller gate drive?

Yes. With V_GS(th) ranging from 2.0V to 4.0V and guaranteed R_DS(on) at V_GS = 4.5V (0.055Ω typ.), the IRFL4105 fully enhances using 3.3V logic outputs. However, for lowest R_DS(on), a 5V or 10V gate drive is recommended to achieve 0.045Ω.

What is the maximum PCB copper area needed to achieve 2.1W power dissipation?

The 2.1W rating applies only when mounted on a 1-inch square copper board (R_θJA = 50°C/W). On standard FR-4 with minimum footprint, the practical limit remains 1.0W (R_θJA = 90°C/W). To reach 2.1W, a dedicated 25.4mm × 25.4mm copper pour with ≥6 thermal vias to inner ground layers is required.

Does IRFL4105 require a gate resistor for stability?

A gate resistor (typically 10–47Ω) is recommended to dampen parasitic oscillation during switching, especially when driving inductive loads. The device's Q_gd/Q_gs ratio (≈2.9) indicates moderate Miller effect; omitting the resistor may cause shoot-through in half-bridge configurations.

Can IRFL4105 replace IRFL014 in existing designs?

No. Although both use SOT-223, the IRFL014 has V_DSS = 60V and R_DS(on) = 0.27Ω - significantly higher on-resistance and different thermal profile. Substituting IRFL4105 would reduce conduction loss but risks overvoltage failure if the original design relied on 60V margin; layout and SOA validation are mandatory.

IRFL4105 Specifications

Product attributes: Attribute value

Manufacturer:: Infineon Technologies

Series:: HEXFET®

Package/Case:: TO-261-4, TO-261AA

Packaging:: Tube

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 55 V

Current - Continuous Drain (Id) @ 25°C:: 3.7A (Ta)

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

Rds On (Max) @ Id, Vgs:: 45mOhm @ 3.7A, 10V

Vgs(th) (Max) @ Id:: 4V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 35 nC @ 10 V

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 660 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 1W (Ta)

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-223

IRFL4105 FAQ

1.How can I place an order for IRFL4105 through Aetrix?

Please submit a Request for Quotation (RFQ) for IRFL4105 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 IRFL4105 reliable?

The price and inventory of IRFL4105 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IRFL4105 is usually 5 days.

3.What payment methods are accepted for IRFL4105?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IRFL4105 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for IRFL4105?

IRFL4105 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your IRFL4105 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 IRFL4105?

For technical support, including IRFL4105 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IRFL4105 requirements.

6.How does Aetrix verify that IRFL4105 is sourced from the original manufacturer or authorized distributors?

All IRFL4105 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 IRFL4105 meets industry standards.

7.What is the process for return or replacement of IRFL4105?

All IRFL4105 units undergo pre-shipment inspection (PSI). If there is an issue with IRFL4105, 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 IRFL4105 part is unused and in its original packaging.

Return procedure for IRFL4105:

1.Submit a request within 90 days.

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

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