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

Infineon Technologies IRLU4343PBF

Name: IRLU4343PBF
Brand: Infineon Technologies
SKU: IRLU4343PBF
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: IRLU4343PBF

Manufacturer:: Infineon Technologies

Category:: FETs, MOSFETs

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

Datasheet:: IRLU4343PBF.pdf

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

Quantity:: RFQ Add To RFQ list

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Inventory:8,183

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Product details

Overview

IRLU4343PBF 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) @ 10 V, 28 nC total gate charge, and 175°C maximum junction temperature, enabling high-efficiency switching with low THD and EMI in compact audio power modules.

For engineers reviewing the IRLU4343PBF datasheet, IRLU4343PBF pinout, IRLU4343PBF application, or IRLU4343PBF equivalent, key selection criteria include its low Q_rr (100–150 nC), fast body diode recovery (t_rr = 52–78 ns), and repetitive avalanche rating-critical for unclamped inductive switching in bridge-tied load (BTL) amplifiers.

Technical Context

This MOSFET employs advanced HEXFET® process technology to minimize conduction and switching losses simultaneously. Its gate charge profile (Q_gd = 9.5 nC, Q_gs = 3.5 nC) and low internal source/drain inductance (L_S = 7.5 nH, L_D = 4.5 nH) are tuned to suppress voltage overshoot and ringing during hard-switching transitions in high-frequency Class-D topologies.

The device integrates a robust body diode with V_SD ≤ 1.2 V at 19 A and exhibits specified repetitive avalanche capability (E_AR = 100 mJ @ T_J = 25°C), allowing reliable operation under transient overcurrent conditions without external snubbers in BTL half-bridge configurations.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	55 V - Supports rail voltages up to ±25 V in dual-supply Class-D amplifiers with margin against transients.
R_DS(on) @ 10 V	42 mΩ - Enables <1.5 W conduction loss at 19 A continuous drain current in D-Pak package.
Q_g	28 nC - Reduces gate drive power and enables use of low-current gate drivers (e.g., IR2011) without excessive heating.
Q_rr	100–150 nC - Low reverse recovery charge minimizes shoot-through risk and EMI generation during dead-time commutation.
t_rr	52–78 ns - Fast body diode recovery supports >300 kHz switching frequencies while maintaining THD < 0.01%.
T_J(max)	175°C - Allows sustained operation at elevated ambient temperatures in sealed audio enclosures without derating.
R_θJC	1.9 °C/W - Enables direct heatsinking via D-Pak tab for thermal management in space-constrained PCB layouts.

Pinout & Package

D-Pak (TO-252AA) package with exposed drain pad on bottom side for thermal conduction and mechanical mounting. Three-terminal surface-mount configuration.

Pin/Terminal	Circuit Role	Design Meaning
Drain (Tab)	Main current path from source to load	Exposed metal tab serves as primary heat sink interface and carries full output current; must be soldered to copper pour.
Source	Reference node for gate control and return path	Connected to power ground or low-side switch node; low-inductance layout critical to minimize switching noise coupling.
Gate	Control electrode for channel conduction	High-impedance input requiring controlled slew rate; gate resistor selection balances switching speed vs. EMI and dV/dt-induced turn-on.

Key Features

Feature	Design Value
Optimized Q_g/Q_sw ratio	Enables efficient zero-voltage switching (ZVS) in resonant Class-D topologies without increasing gate drive complexity.
Low Q_rr body diode	Reduces energy loss and voltage spikes during freewheeling, directly lowering THD and audible noise in mid/high-frequency bands.
175°C rated junction	Eliminates need for thermal derating in automotive infotainment systems operating at 85°C ambient with 20 K thermal margin.
Repetitive avalanche capability	Withstands ≥160 mJ single-pulse avalanche energy, enabling robust operation during speaker short-circuit or clipping events.

Applications

Home Audio Amplifiers

Automotive Infotainment Systems

Use Scenario: High-fidelity stereo amplifier delivering 100 W per channel into 4 Ω loads using half-bridge BTL topology.

IC Role / Device Role / Timing Role: Output power switch in PWM-driven H-bridge stage; switches at 350–400 kHz with 50 ns dead time.

Use Value: 42 mΩ R_DS(on) and 28 nC Q_g reduce total power loss to <2.1 W per device at full output, enabling passive cooling.

Use Scenario: Compact 4×50 W DSP-controlled amplifier module mounted behind dashboard with limited airflow.

IC Role / Device Role / Timing Role: High-side and low-side switch in Class-D output stage; operates continuously at 125°C case temperature.

Use Value: 175°C T_J(max) and 1.9 °C/W R_θJC allow stable operation without thermal throttling under sustained bass-heavy program material.

Professional Sound Mixers

Active Speaker Crossovers

Use Scenario: Multi-channel monitor controller with independent 30 W Class-D outputs per channel for studio reference monitors.

IC Role / Device Role / Timing Role: Final-stage power switch handling rapid dynamic transients (e.g., drum hits) with minimal distortion.

Use Value: Low Q_rr (100 nC) and fast t_rr (52 ns) prevent body-diode conduction artifacts that degrade transient response and imaging accuracy.

Use Scenario: Bi-amplified active loudspeaker with separate Class-D amplifiers for woofer and tweeter sections.

IC Role / Device Role / Timing Role: Output switch in high-frequency amplifier section switching above 500 kHz to support ultrasonic carrier suppression.

Use Value: Optimized C_iss/C_oss ratio (740 pF / 150 pF) ensures stable gate drive impedance and predictable rise/fall times up to 600 kHz.

Equivalent & Alternatives

The following parts are listed as comparable options for similar Class-D audio MOSFET applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
STW48N65M5	650 V, 48 A, TO-247; higher V_DS, larger package, 3x higher Q_g	Designed for industrial SMPS, not optimized for audio THD/EMI	Use only if higher voltage rating or higher current headroom is required; requires stronger gate driver and larger heatsink.
IPP60R099C7	600 V, 50 A, TO-220; CoolMOS™ superjunction; lower R_DS(on) but higher Q_rr (220 nC)	Targeted at PFC and LLC converters; body diode unsuited for hard-commutated audio bridges	Not recommended for Class-D due to excessive Q_rr-induced THD; avoid in BTL configurations without active clamping.

Compared with STW48N65M5 and IPP60R099C7, the IRLU4343PBF provides the optimal balance of low Q_rr, fast t_rr, and D-Pak thermal performance specifically validated for audio-grade switching-making it the preferred choice where THD, EMI, and board area are design constraints.

Availability

IRLU4343PBF is available at Aetrix Electronics and suitable for home audio amplifiers, automotive infotainment systems, professional sound mixers, and active speaker crossovers requiring stable component supply and long-term production continuity.

Supply support for IRLU4343PBF 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 expertise in high-efficiency power conversion and rugged discrete solutions.

This device belongs to Infineon's HEXFET® Power MOSFET product line, engineered specifically for high-frequency, high-reliability switching in audio, motor control, and DC-DC applications where low conduction loss and controlled switching behavior are essential.

FAQ

What is the maximum continuous drain current for IRLU4343PBF at 100°C case temperature?

The IRLU4343PBF 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 rating assumes proper PCB copper area (≥1 in² 2 oz Cu) and no airflow, leveraging its 1.9 °C/W R_θJC for thermal transfer to an external heatsink.

Does IRLU4343PBF require a gate resistor, and what value is recommended?

Yes-a gate resistor is required to control dV/dt and prevent parasitic oscillation. For typical Class-D operation at 350–400 kHz, a 10–22 Ω non-inductive resistor between driver output and gate is recommended. Lower values increase switching speed but raise EMI; higher values reduce ringing but increase switching losses.

Can IRLU4343PBF be used in synchronous rectification applications?

No-it is not designed or characterized for synchronous rectification. Its body diode parameters (Q_rr, t_rr) are optimized for Class-D freewheeling, not for low-loss reverse conduction. Synchronous rectifier MOSFETs require bidirectional low R_DS(on) and symmetric diode characteristics not present here.

Is the D-Pak package of IRLU4343PBF lead-free and RoHS compliant?

Yes-the "PBF" suffix confirms lead-free (Pb-free) construction and full compliance with EU RoHS Directive 2011/65/EU. The device uses matte tin plating on leads and meets JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1), allowing unlimited floor life at ≤30°C/60% RH.

IRLU4343PBF 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

IRLU4343PBF FAQ

1.How can I place an order for IRLU4343PBF through Aetrix?

Please submit a Request for Quotation (RFQ) for IRLU4343PBF 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 IRLU4343PBF reliable?

The price and inventory of IRLU4343PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IRLU4343PBF is usually 5 days.

3.What payment methods are accepted for IRLU4343PBF?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IRLU4343PBF transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for IRLU4343PBF?

IRLU4343PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your IRLU4343PBF 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 IRLU4343PBF?

For technical support, including IRLU4343PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IRLU4343PBF requirements.

6.How does Aetrix verify that IRLU4343PBF is sourced from the original manufacturer or authorized distributors?

All IRLU4343PBF 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 IRLU4343PBF meets industry standards.

7.What is the process for return or replacement of IRLU4343PBF?

All IRLU4343PBF units undergo pre-shipment inspection (PSI). If there is an issue with IRLU4343PBF, 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 IRLU4343PBF part is unused and in its original packaging.

Return procedure for IRLU4343PBF:

1.Submit a request within 90 days.

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

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