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

Infineon Technologies IRLR4343

Name: IRLR4343
Brand: Infineon Technologies
SKU: IRLR4343
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: IRLR4343

Manufacturer:: Infineon Technologies

Category:: FETs, MOSFETs

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

Datasheet:: IRLR4343.pdf

Description:: MOSFET N-CH 55V 26A DPAK

Quantity:: RFQ Add To RFQ list

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Inventory:2,547

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Product details

Overview

IRLR4343 from Infineon Technologies (formerly International Rectifier) is a 55 V, 26 A N-channel enhancement-mode MOSFET in I-Pak (TO-252AA) package, 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 junction rating, enabling high-efficiency switching with low THD and EMI in compact audio power modules.

For engineers reviewing the IRLR4343 datasheet, IRLR4343 pinout, IRLR4343 application, or IRLR4343 equivalent, this device is selected for its low Q_rr (100–150 nC), fast switching (t_r = 19 ns, t_f = 5.3 ns), and robust repetitive avalanche capability-critical for unclamped inductive turn-off in bridge-tied load (BTL) amplifiers.

Technical Context

The IRLR4343 employs advanced HEXFET® process technology to minimize conduction and switching losses simultaneously. Its low Q_g/Q_sw ratio and optimized body diode (t_rr = 52–78 ns, Q_rr = 100–150 nC) reduce crossover distortion and EMI generation during high-frequency PWM operation typical of Class-D topologies.

Designed for surface-mount PCB mounting with R_θJC = 1.9°C/W, it supports thermal management in dense audio amplifier layouts. The 175°C T_J_max and rated repetitive avalanche energy (E_AR) enable reliable operation under transient overloads and short-circuit conditions without external protection circuitry.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DS	55 V - Withstands rail voltages up to ±28 V in BTL configurations with margin for voltage spikes.
R_DS(on) @ 10 V	42 mΩ typ. - Enables <1.2 W conduction loss at 19 A DC, critical for thermal budget in sealed enclosures.
Q_g	28 nC typ. - Reduces gate drive power and allows use of lower-current drivers in cost-sensitive designs.
Q_rr	100–150 nC - Minimizes body-diode recovery-induced shoot-through and audible distortion in half-bridge switching.
t_r/t_f	19 ns / 5.3 ns - Supports >500 kHz PWM frequencies while maintaining clean edge integrity and low EMI.
T_J_max	175°C - Allows sustained operation in high ambient environments (e.g., automotive infotainment, powered speakers).
E_AS	160 mJ - Absorbs single-pulse inductive energy from speaker loads without failure, eliminating need for snubbers.

Pinout & Package

I-Pak (TO-252AA) package with exposed drain pad for thermal conduction and mechanical stability. Standard 3-pin configuration with dual drain leads (pins 2 and 4) for current sharing and reduced parasitic inductance.

Pin/Terminal	Circuit Role	Design Meaning
1	GATE	Control input requiring ≤10 V logic-level drive; low C_iss (740 pF) minimizes driver loading.
2 & 4	DRAIN	High-side switch node connection; dual pins reduce current density and bond-wire inductance in BTL outputs.
3	SOURCE	Power ground reference for gate drive and current sensing; tied to PCB ground plane via thermal pad.

Key Features

Feature	Design Value
Optimized Class-D switching performance	Low Q_g/Q_sw ratio and tailored C_oss/C_rss reduce THD below 0.01% at 1 kHz full power.
Repetitive avalanche rated	Rated for continuous unclamped inductive switching (E_AR = 140 mJ @ T_J = 125°C), enabling robust BTL bridge operation.
Thermally rugged construction	175°C T_J_max and R_θJC = 1.9°C/W allow 26 A continuous current with minimal heatsinking in 4-layer PCBs.
Low body-diode reverse recovery	Q_rr = 100–150 nC and t_rr = 52–78 ns suppress voltage overshoot and ringing during dead-time transitions.

Applications

Home Audio Amplifiers

Automotive Infotainment Systems

Use Scenario: High-fidelity Class-D amplifier module delivering 100 W into 4 Ω in compact AV receivers.

IC Role / Device Role / Timing Role: Output stage half-bridge switch handling 500 kHz PWM with synchronous rectification.

Use Value: 42 mΩ R_DS(on) and 28 nC Q_g enable >92% efficiency at full power, reducing heatsink volume by 40% vs. legacy MOSFETs.

Use Scenario: 4-channel DSP-controlled amplifier in premium vehicle sound systems with active noise cancellation.

IC Role / Device Role / Timing Role: High-side and low-side switch in BTL output stage operating at 300–600 kHz with adaptive dead-time control.

Use Value: Repetitive avalanche rating eliminates need for external clamping diodes, simplifying layout and improving EMC compliance.

Powered Studio Monitors

Professional PA System Modules

Use Scenario: Bi-amplified near-field monitor with separate LF/HF channels, each using discrete MOSFET output stages.

IC Role / Device Role / Timing Role: Primary switching element in 200 W LF channel, handling peak currents >40 A with <10 µs rise/fall times.

Use Value: Dual drain pins (pins 2 & 4) reduce effective source inductance (L_S = 7.5 nH), suppressing gate oscillation and improving stability at 1 MHz+ switching.

Use Scenario: 500 W modular amplifier card for touring-grade line arrays, operating in forced-air-cooled chassis.

IC Role / Device Role / Timing Role: Output switch in high-efficiency H-bridge topology with real-time current limiting and thermal foldback.

Use Value: 175°C T_J_max and 1.9°C/W R_θJC support continuous 26 A operation at 70°C ambient, enabling 30% higher power density than industry standard.

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
IRFZ44NPBF	R_DS(on) = 28 mΩ @ 10 V but Q_g = 67 nC; no specified Q_rr or avalanche rating.	Lacks Class-D-optimized body diode; higher switching loss increases THD above 10 kHz.	Select only for DC/low-frequency switching where gate drive strength exceeds 1 A and thermal margin is ample.
STP55NF06L	R_DS(on) = 14 mΩ @ 10 V but T_J_max = 175°C and Q_rr = 220 nC; TO-220 package.	Higher Q_rr degrades THD in high-frequency PWM; larger package limits board space efficiency.	Prefer for high-current linear-regulated supplies, not Class-D audio where EMI and efficiency dominate.

Compared with IRFZ44NPBF and STP55NF06L, the IRLR4343 uniquely balances low R_DS(on), low Q_g, low Q_rr, and repetitive avalanche capability in a thermally efficient surface-mount package-making it the only validated choice for high-fidelity, space-constrained Class-D amplifier output stages.

Availability

IRLR4343 is available at Aetrix Electronics and suitable for home audio amplifiers, automotive infotainment systems, and powered studio monitors requiring stable component supply and long-term production continuity.

Supply support for IRLR4343 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 acquired International Rectifier in 2015 and continues its legacy of high-performance power semiconductors for industrial, automotive, and consumer applications.

The IRLR4343 belongs to the HEXFET® Class-D Audio MOSFET product line, engineered specifically to meet the stringent efficiency, THD, and reliability requirements of modern digital audio amplification architectures.

FAQ

Is the IRLR4343 suitable for 12 V automotive audio applications?

Yes. With V_DS = 55 V and 175°C T_J_max, the IRLR4343 safely handles automotive load-dump transients (up to 40 V) and operates reliably at ambient temperatures up to 105°C. Its low R_DS(on) ensures minimal voltage drop across the MOSFET in 12 V supply rails, preserving headroom for high-output audio stages.

What is the recommended gate resistor value for optimal Class-D switching?

A 2.5 Ω gate resistor is specified in the datasheet for switching characterization (t_d(on), t_r). For production designs, values between 1.5 Ω and 4.7 Ω balance EMI suppression and switching speed. Lower values increase dV/dt stress on gate drivers; higher values degrade THD above 20 kHz due to slowed edge rates.

Does the IRLR4343 require a negative gate voltage for safe turn-off?

No. The IRLR4343 has a gate threshold voltage (V_GS(th)) of 1.0–2.5 V and is fully enhanced at 4.5 V. A 0 V gate drive fully turns off the device. Negative gate bias is unnecessary and may risk exceeding the ±20 V V_GS absolute maximum rating if improperly implemented.

Can the IRLR4343 be paralleled for higher current capacity?

Yes. Its positive temperature coefficient for R_DS(on) (see Fig. 4) enables inherent current sharing. Use matched gate resistors (≤5% tolerance), symmetrical PCB layout, and shared thermal plane. Derate total current by 15% versus sum of individual ratings to account for thermal coupling and parameter spread.

IRLR4343 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):: 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:: -40°C ~ 175°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

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

IRLR4343 FAQ

1.How can I place an order for IRLR4343 through Aetrix?

Please submit a Request for Quotation (RFQ) for IRLR4343 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 IRLR4343 reliable?

The price and inventory of IRLR4343 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IRLR4343 is usually 5 days.

3.What payment methods are accepted for IRLR4343?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IRLR4343 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for IRLR4343?

IRLR4343 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your IRLR4343 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 IRLR4343?

For technical support, including IRLR4343 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IRLR4343 requirements.

6.How does Aetrix verify that IRLR4343 is sourced from the original manufacturer or authorized distributors?

All IRLR4343 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 IRLR4343 meets industry standards.

7.What is the process for return or replacement of IRLR4343?

All IRLR4343 units undergo pre-shipment inspection (PSI). If there is an issue with IRLR4343, 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 IRLR4343 part is unused and in its original packaging.

Return procedure for IRLR4343:

1.Submit a request within 90 days.

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

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