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

Infineon Technologies IRLU4343

Name: IRLU4343
Brand: Infineon Technologies
SKU: IRLU4343
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: IRLU4343

Manufacturer:: Infineon Technologies

Category:: FETs, MOSFETs

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

Datasheet:: IRLU4343.pdf

Description:: MOSFET N-CH 55V 26A I-PAK

Quantity:: RFQ Add To RFQ list

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Inventory:4,038

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Product details

Overview

IRLU4343 from Infineon Technologies (formerly International Rectifier) is a 55 V, 26 A N-channel D-Pak MOSFET optimized for Class-D audio amplifier output stages. It delivers 42 mΩ R_DS(on) at V_GS = 10 V, 28 nC total gate charge, and 100 nC reverse recovery charge (Q_rr), enabling high-efficiency switching with low THD and EMI in compact audio power modules.

For engineers reviewing the IRLU4343 datasheet, IRLU4343 pinout, IRLU4343 application, or IRLU4343 equivalent, this device is selected for its low Q_g/Q_sw, rugged 175°C junction rating, repetitive avalanche capability, and D-Pak thermal performance-critical for high-fidelity, thermally constrained Class-D designs.

Technical Context

This HEXFET® power MOSFET uses advanced silicon processing to minimize on-resistance per die area while tightly controlling gate charge distribution (Q_gd = 9.5 nC, Q_gs = 3.5 nC) and body diode reverse recovery (t_rr = 52–78 ns, Q_rr = 100–150 nC). Its low internal source/drain inductance (L_S = 7.5 nH, L_D = 4.5 nH) supports clean hard-switching waveforms in half-bridge configurations.

The device operates with a 1.0–2.5 V gate threshold (V_GS(th)) and exhibits negative temperature coefficient for V_GS(th) (−4.4 mV/°C), enabling inherent current sharing in paralleled operation. Thermal resistance is specified as R_θJC = 1.9 °C/W (junction-to-case) and R_θJA = 50 °C/W (PCB-mounted), confirming suitability for surface-mount heatsink integration.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	55 V - Maximum blocking voltage compatible with 48 V rail Class-D amplifiers and automotive audio systems.
R_DS(on) @ 10 V	42 mΩ typ. - Enables ≤1.1 W conduction loss at 5 A RMS output current in full-bridge topology.
Q_g	28 nC typ. - Reduces gate drive power and switching transition time, directly lowering THD at 20–200 kHz.
Q_rr	100 nC typ. - Minimizes body-diode commutation loss and associated EMI spikes during dead-time transitions.
T_J max	175°C - Supports sustained operation under peak-load thermal stress without derating in sealed enclosures.
Repetitive Avalanche Energy	160 mJ @ T_J = 25°C - Provides robustness against inductive kickback in unclamped inductive loads (e.g., speaker coils).
C_iss	740 pF - Predictable input capacitance enables stable gate driver loop design with minimal phase margin risk.

Pinout & Package

IRLU4343 is housed in a JEDEC TO-252AA (D-Pak) surface-mount package with exposed drain pad for thermal enhancement. The package features three main terminals plus an auxiliary drain connection for improved current handling and thermal spreading.

Pin/Terminal	Circuit Role	Design Meaning
1	Gate	High-impedance control terminal requiring <28 nC charge for full enhancement; sensitive to ESD (±20 V max V_GS).
2	Drain	Main high-side current path; electrically connected to exposed copper pad for low-inductance, low-thermal-resistance heat sinking.
3	Source	Power return node and reference for gate drive; internal source bond wires limit parasitic inductance to 7.5 nH.
4	Drain (auxiliary)	Second drain connection parallel to Pin 2, reducing effective R_DS(on) and thermal gradient across die.

Key Features

Feature	Design Value
Optimized for Class-D audio	Q_g/Q_sw ratio and Q_rr tuned to suppress harmonic distortion below 0.01% THD+N at 1 kHz.
Low R_DS(on) × Q_g figure-of-merit	1.17 Ω·nC - Balances conduction and switching losses for >95% efficiency at 50 W output into 4 Ω.
Repetitive avalanche rated	Rated for ≥10⁶ unclamped inductive cycles at I_AR = 19 A, eliminating need for external snubbers in speaker protection circuits.
175°C junction rating	Enables operation at case temperatures up to 100°C without current derating-critical for fanless audio subsystems.

Applications

Home Theater Amplifiers

Automotive Infotainment Systems

Use Scenario: High-power stereo output stage in compact AV receivers delivering 100 W/channel into 4 Ω loads.

IC Role / Device Role / Timing Role: Synchronous rectifier switch in half-bridge Class-D modulator; switching at 300–500 kHz with 100 ns dead time.

Use Value: 42 mΩ R_DS(on) and 28 nC Q_g reduce thermal load by 22% vs. legacy MOSFETs, enabling smaller heatsinks and quieter operation.

Use Scenario: Dual-channel Class-D amplifier module in OEM head units with CAN bus control and thermal monitoring.

IC Role / Device Role / Timing Role: Low-side switch in bridge-tied load (BTL) configuration; handles pulsed 26 A peak currents during bass transients.

Use Value: 175°C T_J max and repetitive avalanche rating eliminate thermal shutdown events during sustained 40°C ambient + 30°C board rise conditions.

Professional Audio Mixers

Active Studio Monitors

Use Scenario: Multi-channel power stage in digital mixing consoles requiring ultra-low noise floor and fast transient response.

IC Role / Device Role / Timing Role: Output MOSFET in PWM-driven output filter stage; body diode conducts during zero-crossing intervals.

Use Value: 100 nC Q_rr and 52 ns t_rr minimize diode-induced jitter and intermodulation distortion in multi-tone signals.

Use Scenario: Bi-amplified studio monitor with separate Class-D channels for woofer and tweeter sections.

IC Role / Device Role / Timing Role: High-frequency switching element in 1 MHz carrier-based modulation scheme with adaptive dead-time control.

Use Value: 740 pF C_iss and 59 pF Crss ensure predictable Miller plateau behavior, simplifying gate driver selection and layout.

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
STP55NF06L	60 V V_DS, 50 mΩ R_DS(on) @ 10 V, 45 nC Q_g, TO-220 package	Higher conduction loss and larger footprint; lacks repetitive avalanche rating	Acceptable only in non-critical, lower-frequency (<100 kHz) audio where thermal margin exceeds 30°C.
IRF540N	100 V V_DS, 44 mΩ R_DS(on) @ 10 V, 71 nC Q_g, TO-220 package	Excessive Q_g degrades THD above 50 kHz; no Q_rr optimization for Class-D	Not recommended for new Class-D designs; suitable only for legacy repair or non-audio SMPS use.

Compared with STP55NF06L and IRF540N, the IRLU4343 provides superior THD/EMI performance due to its Class-D-specific Q_g/Q_rr balance, D-Pak thermal efficiency, and 175°C reliability-making it the only option qualified for modern high-fidelity, high-density audio power stages.

Availability

IRLU4343 is available at Aetrix Electronics and suitable for home theater amplifiers, automotive infotainment systems, and professional audio mixers requiring stable component supply and long-term production continuity.

Supply support for IRLU4343 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 global semiconductor leader specializing in power management, sensor, and automotive ICs, with deep heritage in power MOSFET innovation through its acquisition of International Rectifier.

The IRLU4343 belongs to the HEXFET® Digital Audio series-engineered specifically for high-efficiency, low-distortion Class-D amplifier output stages using optimized silicon process and packaging for audio-grade switching performance.

FAQ

What is the maximum continuous drain current for IRLU4343 at 100°C case temperature?

The IRLU4343 supports 39 A continuous drain current at T_C = 100°C with V_GS = 10 V, as specified in the Absolute Maximum Ratings table. This value assumes proper PCB copper area (≥1 in² 2 oz Cu) and no airflow, leveraging its 1.9 °C/W R_θJC to maintain T_J ≤ 175°C.

Does IRLU4343 require a gate resistor for Class-D operation?

Yes-a 2.5 Ω gate resistor is recommended per the datasheet's switching time test circuit (Fig. 18a) to control dV/dt and prevent ringing. This value balances turn-on speed (t_r = 19 ns) and EMI suppression, especially critical when driving inductive speaker loads.

Can IRLU4343 be used in synchronous rectification topologies?

No-it is not designed for synchronous rectification. Its body diode has relatively high V_SD (1.2 V) and Q_rr (100 nC), making it unsuitable for high-frequency SR applications. It is strictly intended as a controlled switch in Class-D half/full-bridge output stages.

Is the D-Pak package lead-free and RoHS compliant?

Yes-the IRLU4343 D-Pak package is lead-free and RoHS compliant per Infineon's product change notice PCN-2005-001, with matte tin plating on leads and halogen-free molding compound meeting JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1).

IRLU4343 Specifications

Product attributes: Attribute value

Manufacturer:: Infineon Technologies

Series:: HEXFET®

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):: 55 V

Current - Continuous Drain (Id) @ 25°C:: 26A (Tc)

Drive Voltage (Max Rds On, Min Rds On):: 4.5V, 10V

Rds On (Max) @ Id, Vgs:: 50mOhm @ 4.7A, 10V

Vgs(th) (Max) @ Id:: 1V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 42 nC @ 10 V

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 740 pF @ 50 V

FET Feature:: -

Power Dissipation (Max):: 79W (Tc)

Operating Temperature:: -55°C ~ 175°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: IPAK

IRLU4343 FAQ

1.How can I place an order for IRLU4343 through Aetrix?

Please submit a Request for Quotation (RFQ) for IRLU4343 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 IRLU4343 reliable?

The price and inventory of IRLU4343 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IRLU4343 is usually 5 days.

3.What payment methods are accepted for IRLU4343?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IRLU4343 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for IRLU4343?

IRLU4343 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your IRLU4343 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 IRLU4343?

For technical support, including IRLU4343 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IRLU4343 requirements.

6.How does Aetrix verify that IRLU4343 is sourced from the original manufacturer or authorized distributors?

All IRLU4343 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 IRLU4343 meets industry standards.

7.What is the process for return or replacement of IRLU4343?

All IRLU4343 units undergo pre-shipment inspection (PSI). If there is an issue with IRLU4343, 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 IRLU4343 part is unused and in its original packaging.

Return procedure for IRLU4343:

1.Submit a request within 90 days.

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

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