Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

Infineon Technologies IRLU3705Z

Name: IRLU3705Z
Brand: Infineon Technologies
SKU: IRLU3705Z
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: IRLU3705Z

Manufacturer:: Infineon Technologies

Category:: FETs, MOSFETs

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

Datasheet:: IRLU3705Z.pdf

Description:: MOSFET N-CH 55V 42A I-PAK

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:2,238

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

IRLU3705Z from Infineon Technologies is an N-channel logic-level HEXFET® Power MOSFET in D-Pak (TO-252) package, rated for 55V V_DSS, 8.0mΩ R_DS(on) at V_GS = 10V, and 42A continuous drain current at T_C = 25°C. It features 175°C maximum junction temperature, fast switching (t_r = 150ns, t_f = 70ns), and rated repetitive avalanche capability-designed specifically for automotive load switching, DC-DC converters, and motor control.

For engineers reviewing the IRLU3705Z datasheet, IRLU3705Z pinout, IRLU3705Z application, or IRLU3705Z equivalent, key selection criteria include its low R_DS(on) at 4.5V gate drive, robust avalanche energy rating (E_AS = 89mJ), body diode reverse recovery performance (Q_rr = 14–28nC), and thermal resistance (R_θJC = 1.14°C/W).

Technical Context

This MOSFET employs advanced silicon processing to minimize on-resistance per die area while maintaining high ruggedness. Its logic-level gate threshold (V_GS(th) = 1.0–3.0V) enables direct drive from microcontrollers and low-voltage PWM controllers without gate drivers.

The device integrates a co-packaged body diode with characterized reverse recovery (t_rr = 21–42ns, Q_rr = 14–28nC) and supports unclamped inductive switching up to T_jmax. Thermal design is enabled by validated transient impedance curves and a low R_θJC of 1.14°C/W for efficient heatsinking in automotive under-hood environments.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DSS	55V - Maximum blocking voltage before avalanche; suitable for 48V automotive systems and 36V industrial rails.
R_DS(on) @ V_GS = 10V	6.5–8.0mΩ - Enables <1.7W conduction loss at 42A, critical for thermally constrained engine-control modules.
I_D Continuous @ T_C = 25°C	42A - Silicon-limited current handling; derates to ~25A at T_C = 100°C per Fig.9.
Q_g Total Gate Charge	44–66nC - Determines gate driver power requirement; compatible with standard 1A peak drivers at ≤100kHz switching.
E_AS Single-Pulse Avalanche Energy	89mJ - Validated energy limit for unclamped inductive turn-off; supports robust solenoid and relay driving.
T_J Operating Range	−55°C to +175°C - Qualified for under-hood automotive use per AEC-Q101; no derating required up to 150°C ambient.
V_SD Body Diode Forward Voltage	≤1.3V @ I_S = 42A - Low forward drop reduces freewheeling losses in H-bridge and synchronous rectifier topologies.

Pinout & Package

IRLU3705Z uses the D-Pak (TO-252) surface-mount package with exposed drain pad for thermal enhancement. The three-terminal configuration supports high-current PCB routing and direct heatsink mounting via the drain tab.

Pin/Terminal	Circuit Role	Design Meaning
Drain (D)	Main current-carrying terminal, connected to internal die substrate	Exposed metal pad on bottom of package; primary thermal path to PCB copper or heatsink; must be soldered for R_θJC = 1.14°C/W.
Source (S)	Reference node for gate drive and current return path	Low-inductance connection point for gate driver ground and load return; LS = 7.5nH limits switching ringing.
Gate (G)	Control electrode for channel formation	High-impedance input requiring <66nC charge; threshold range (1.0–3.0V) ensures compatibility with 3.3V/5V logic.

Key Features

Feature	Design Value
Logic-level gate drive	Operates fully enhanced at V_GS = 4.5V (R_DS(on) ≤ 12mΩ), eliminating need for level-shifting in MCU-based control.
Repetitive avalanche rated	Validated for repeated unclamped inductive switching up to T_jmax; enables reliable operation in relay/solenoid drivers without snubbers.
Ultra-low R_DS(on)	6.5mΩ typical at 10V drive reduces conduction loss by >30% vs. legacy 55V MOSFETs, improving efficiency in 12V/24V battery systems.
175°C junction rating	Supports full-rated performance in high-ambient automotive zones (e.g., transmission control units) without thermal derating.
Fast body diode recovery	t_rr = 21ns typical and Q_rr = 14nC enable clean commutation in synchronous buck and half-bridge converters.

Applications

Automotive Engine Control

Industrial DC Motor Drive

Use Scenario: High-side switching of fuel injectors and ignition coils in ECU modules.

IC Role / Device Role / Timing Role: Power switch controlling inductive loads with precise 1–10ms pulse width and 100V flyback suppression.

Use Value: Rated avalanche energy (89mJ) absorbs inductive kickback without external clamping; 175°C rating sustains operation near hot engine blocks.

Use Scenario: Half-bridge leg in 24V brushed DC motor controllers for factory automation actuators.

IC Role / Device Role / Timing Role: Low-side switching element with fast turn-off (t_f = 70ns) to minimize shoot-through risk during PWM commutation.

Use Value: 4.5V logic-level gate enables direct STM32 GPIO drive; low Q_g (44nC) supports 50kHz PWM without excessive gate loss.

48V Mild Hybrid Systems

Server PSU OR-ing

Use Scenario: Load switch for 48V battery disconnect and pre-charge circuits in P0/P1 hybrid architectures.

IC Role / Device Role / Timing Role: High-current (42A) bidirectional blocking switch with controlled turn-on slew rate to limit inrush.

Use Value: R_DS(on) = 8.0mΩ limits power dissipation to <15W at full load, enabling compact heatsinkless designs in space-constrained enclosures.

Use Scenario: OR-ing FET in redundant 12V server power supply outputs to prevent backfeed and improve fault isolation.

IC Role / Device Role / Timing Role: Low-V_DS forward conduction path with body diode bypassed during normal operation.

Use Value: V_SD ≤ 1.3V and fast t_rr reduce reverse recovery losses during hot-swap events, improving system MTBF.

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
STL120N5LF8AG	R_DS(on) = 5.2mΩ @ 10V, but V_DSS = 50V; Q_g = 72nC; TO-263 package	Higher current density but lower breakdown margin; less suited for 48V transients exceeding 50V	Select when max V_DS stays below 45V and lowest conduction loss is prioritized over transient robustness.
ON Semiconductor NTMFS5C675NL	R_DS(on) = 6.7mΩ @ 10V, V_DSS = 60V, Q_g = 52nC; PowerTrench® 5x6mm SO-8FL	Smaller footprint, higher thermal resistance (R_θJA = 50°C/W), no avalanche rating published	Prefer for space-constrained consumer electronics where avalanche immunity is not required and board layout favors DFN.

Compared with STL120N5LF8AG and NTMFS5C675NL, IRLU3705Z offers superior avalanche ruggedness (89mJ), proven automotive qualification, and optimal balance of low gate charge and 55V margin-making it the preferred choice for safety-critical inductive switching in harsh environments.

Availability

IRLU3705Z is available at Aetrix Electronics and suitable for automotive engine control units, industrial DC motor drives, 48V mild hybrid systems, and server OR-ing applications requiring stable component supply across extended product lifecycles.

Supply support for IRLU3705Z 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 leader specializing in power management, automotive electronics, and industrial control ICs, with global manufacturing and AEC-Q101 qualification infrastructure.

The IRLU3705Z belongs to Infineon's HEXFET® Automotive Logic-Level MOSFET family, engineered to replace electromechanical relays and discrete bipolar switches in high-reliability 12V–48V vehicle subsystems.

FAQ

Is IRLU3705Z AEC-Q101 qualified?

Yes, IRLU3705Z is explicitly qualified to AEC-Q101 Rev D for automotive applications. Test reports confirm compliance with stress tests including HTGB, HTRB, uHAST, and repetitive avalanche-documented in Infineon's official automotive qualification summary for the IRLx3705Z series.

What is the maximum safe operating frequency for IRLU3705Z in a 24V motor drive?

At 24V V_DD and 42A load, switching losses dominate above 100kHz due to Q_g = 66nC and t_f = 70ns. Practical maximum is 80–100kHz with 1A gate driver and optimized PCB layout; thermal limits (R_θJC = 1.14°C/W) allow sustained operation if case temperature remains ≤100°C.

Can IRLU3705Z replace IRLR3705Z in existing designs?

Yes-IRLU3705Z (D-Pak) and IRLR3705Z (IPAK) share identical electrical specifications, thermal limits, and pinout assignment (D-S-G). Mechanical substitution requires only footprint adaptation; no circuit or firmware changes are needed, and both meet identical AEC-Q101 requirements.

Does the body diode support synchronous rectification in buck converters?

No-the body diode is not optimized for synchronous rectification. Its Q_rr = 14–28nC and t_rr = 21–42ns cause significant reverse recovery loss at >100kHz. For synchronous operation, use a dedicated Schottky or GaN FET; IRLU3705Z is intended for low-side switching or freewheeling where diode conduction is brief and infrequent.

IRLU3705Z 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:: 42A (Tc)

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

Rds On (Max) @ Id, Vgs:: 8mOhm @ 42A, 10V

Vgs(th) (Max) @ Id:: 3V @ 250µA

Gate Charge (Qg) (Max) @ Vgs:: 66 nC @ 5 V

Vgs (Max):: ±16V

Input Capacitance (Ciss) (Max) @ Vds:: 2900 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 130W (Tc)

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: IPAK

IRLU3705Z FAQ

1.How can I place an order for IRLU3705Z through Aetrix?

Please submit a Request for Quotation (RFQ) for IRLU3705Z 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 IRLU3705Z reliable?

The price and inventory of IRLU3705Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IRLU3705Z is usually 5 days.

3.What payment methods are accepted for IRLU3705Z?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IRLU3705Z transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for IRLU3705Z?

IRLU3705Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your IRLU3705Z 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 IRLU3705Z?

For technical support, including IRLU3705Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IRLU3705Z requirements.

6.How does Aetrix verify that IRLU3705Z is sourced from the original manufacturer or authorized distributors?

All IRLU3705Z 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 IRLU3705Z meets industry standards.

7.What is the process for return or replacement of IRLU3705Z?

All IRLU3705Z units undergo pre-shipment inspection (PSI). If there is an issue with IRLU3705Z, 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 IRLU3705Z part is unused and in its original packaging.

Return procedure for IRLU3705Z:

1.Submit a request within 90 days.

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

Tech Hub

2026-07-29 18650 Battery: Voltage, Capacity, Charging and Pack Design

18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…

2026-07-27 Hall Effect Sensor: Working Principle, Types, Circuits and Applications

Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…

2026-07-20 Product Change Notification (PCN) in Electronic Components: Meaning and Supply Chain Response

Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…

2026-07-19 Blend Door Actuator: Symptoms, Location, Reset and Replacement Guide

A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…

2026-07-17 Raspberry Pi Alternatives: Chip-Level Comparison, Compatibility and Replacement Guide

Engineering guide to Raspberry Pi alternatives, covering chip-level differences, Orange Pi, ROCK, Jetson, Banana Pi, NanoPi, Compute Module, Pico, GPIO, camera, HAT compatibility, and replacement risks…

2026-07-13 How to Test Dynamic Load Response in Low-Voltage High-Current Buck Converters

Engineering guide to dynamic load response testing for high-current buck converters, covering load step setup, slew rate, Vcore undershoot, overshoot, recovery time, probe location, output capacitors a…

2026-07-08 Output Capacitor Selection for High-Current ASIC Vcore Rails

Engineering guide to output capacitor selection for ASIC Vcore rails, covering bulk capacitors, polymer capacitors, MLCC decoupling, DC bias, ESR, ESL, placement, transient response and substitution ri…

2026-07-07 High-Current ASIC Core Power Supply Design: 12-Phase Buck, PMBus and Dynamic Load Response

Engineering guide to high-current ASIC Vcore rails, covering 12-phase buck architecture, PMBus control, dynamic load testing, output capacitor networks, smart power stage selection, thermal design and …

2026-07-06 Voltage Regulator: Types, Circuits, Testing and Selection Guide

Voltage regulator guide covering linear, LDO, 7805, Zener, adjustable, buck, VRM and alternator regulators, with design checks, testing methods, troubleshooting and datasheet-based selection.

2026-06-30 Amplifiers Explained: Types, Circuits, Gain, Classes and Applications

Amplifier guide covering voltage, current and power amplification, gain, feedback, amplifier classes, audio and RF applications, op-amp circuits, transimpedance amplifiers, datasheet selection and trou…