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

Infineon Technologies IRLR3705Z

Name: IRLR3705Z
Brand: Infineon Technologies
SKU: IRLR3705Z
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: IRLR3705Z

Manufacturer:: Infineon Technologies

Category:: FETs, MOSFETs

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

Datasheet:: IRLR3705Z.pdf

Description:: MOSFET N-CH 55V 42A DPAK

Quantity:: RFQ Add To RFQ list

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Product details

Overview

IRLR3705Z from Infineon Technologies is an N-channel logic-level HEXFET® Power MOSFET in D-Pak (TO-252) package, rated for 55V V_DSS, 8.0 mΩ R_DS(on) at V_GS = 10 V, and 42 A continuous drain current at T_C = 25°C. It features 175°C maximum junction temperature, fast switching (t_r = 150 ns, t_f = 70 ns), and rated repetitive avalanche capability - designed specifically for automotive power switching applications including motor control and DC-DC conversion.

For engineers reviewing the IRLR3705Z datasheet, IRLR3705Z pinout, IRLR3705Z application, or IRLR3705Z equivalent, key selection criteria include its low R_DS(on) at 4.5 V gate drive, robust avalanche energy rating (E_AS = 89 mJ), body diode reverse recovery performance (Q_rr = 14–28 nC), and thermal resistance (R_θJC = 1.14 °C/W) for high-reliability under sustained load conditions.

Technical Context

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

The device integrates a fast, low-loss body diode with t_rr = 21–42 ns and V_SD ≤ 1.3 V at 42 A, supporting synchronous rectification and bidirectional current handling in H-bridge and buck-boost topologies. Repetitive avalanche operation is permitted up to T_jmax, validated per AN-1005 test methodology.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DSS	55 V - Maximum blocking voltage before avalanche onset; suitable for 48 V automotive systems with margin.
R_DS(on) @ V_GS = 10 V	6.5–8.0 mΩ - Enables <1 W conduction loss at 42 A, critical for thermally constrained engine bay modules.
I_D Continuous @ T_C = 25°C	42 A - Silicon-limited current rating; requires heatsinking above ~60°C case temperature.
Q_g Total Gate Charge	44–66 nC - Determines driver strength requirement; compatible with standard gate drivers (e.g., IR2104, UCC27531).
E_AS Single-Pulse Avalanche Energy	89 mJ - Supports unclamped inductive switching in motor drives without external snubbers.
T_j Operating Range	−55 to +175°C - Meets AEC-Q101 requirements for under-hood automotive use.
V_GS(th)	1.0–3.0 V - Ensures turn-on with 3.3 V or 5 V logic; eliminates need for gate boosters in low-voltage control stages.

Pinout & Package

IRLR3705Z 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 efficient heat transfer to copper planes.

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (Source)	Source terminal (S)	Low-side reference node; connects to ground or current-sense shunt; internal bond-wire path optimized for low inductance (L_S = 7.5 nH).
Pin 2 (Gate)	Control input (G)	High-impedance MOS gate; requires <200 nA leakage current compliance; sensitive to ESD (HBM Class 1B).
Pin 3 (Drain)	Power output (D)	Exposed metal pad (backside); electrically connected to drain; primary thermal path to PCB; L_D = 4.5 nH limits voltage overshoot during fast switching.

Key Features

Feature	Design Value
Logic-level gate drive compatibility	Operates fully enhanced at V_GS = 4.5 V (R_DS(on) ≤ 12 mΩ), enabling direct MCU GPIO interface.
Repetitive avalanche rated	Validated for repeated unclamped inductive switching up to T_jmax, reducing need for external protection components.
Ultra-low R_DS(on) density	8.0 mΩ in D-Pak delivers >30% lower conduction loss than legacy 55 V MOSFETs in same footprint.
Enhanced body diode performance	Q_rr = 14–28 nC and t_rr = 21–42 ns enable efficient freewheeling in synchronous rectifiers and half-bridges.
Thermal robustness	R_θJC = 1.14 °C/W allows >40 W dissipation with modest heatsinking - critical for space-constrained automotive ECUs.

Applications

Automotive Engine Control Unit (ECU)

48 V Mild Hybrid DC-DC Converter

Use Scenario: High-side switch for fuel injector driver circuits operating at 12–14 V battery supply with 5 ms pulse widths.

IC Role / Device Role / Timing Role: Power switch controlling solenoid actuation; must withstand load dump transients and survive 175°C ambient.

Use Value: 175°C T_j rating and 89 mJ E_AS eliminate need for transient voltage suppressors in injector drive stage.

Use Scenario: Synchronous rectifier in 48 V–12 V bidirectional buck-boost converter for regenerative braking energy recovery.

IC Role / Device Role / Timing Role: Low-side synchronous rectifier with fast body diode recovery to minimize reverse recovery losses at 200 kHz switching.

Use Value: Q_rr = 14–28 nC and V_SD ≤ 1.3 V reduce switching losses by >25% vs. standard Schottky-assisted designs.

Electric Power Steering (EPS) Motor Driver

Commercial Vehicle HVAC Blower Control

Use Scenario: Half-bridge leg in 3-phase inverter driving 24 V brushed DC assist motor with peak currents up to 60 A.

IC Role / Device Role / Timing Role: Low-side switch in H-bridge topology; handles pulsed current with minimal thermal cycling stress.

Use Value: R_DS(on) = 6.5–8.0 mΩ at 10 V ensures <2.5 W conduction loss at 50 A, enabling compact heatsink design.

Use Scenario: PWM-controlled blower fan driver in Class 8 truck cab HVAC system, operating continuously at 24 V, 30 A.

IC Role / Device Role / Timing Role: High-current, high-duty-cycle power switch with integrated thermal protection via junction sensing.

Use Value: 175°C T_j rating and R_θJC = 1.14 °C/W support >95% duty cycle operation without derating.

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	R_DS(on) = 12 mΩ @ 10 V; V_DSS = 60 V; Q_g = 65 nC; TO-220 package	Higher R_DS(on) and through-hole mounting limit suitability for high-density automotive PCBs	Prefer when higher voltage margin (60 V) is required and board space allows TO-220 footprint
AOB414	R_DS(on) = 7.2 mΩ @ 10 V; V_DSS = 60 V; DFN5x6 package; no exposed drain pad	Lower thermal resistance (R_θJC = 0.9 °C/W) but lacks qualified avalanche rating per AEC-Q101	Prefer for non-automotive industrial DC-DC where avalanche robustness is not mandated

Compared with STP55NF06L and AOB414, IRLR3705Z uniquely combines AEC-Q101 qualification, 175°C operation, and D-Pak thermal performance - making it the only option qualified for under-hood automotive switching where both reliability and thermal density are critical.

Availability

IRLR3705Z is available at Aetrix Electronics and suitable for automotive engine control units, 48 V mild hybrid converters, electric power steering systems, and commercial vehicle HVAC blower control requiring stable component supply across extended temperature and lifecycle requirements.

Supply support for IRLR3705Z 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 manufacturer specializing in power management, automotive electronics, and industrial control ICs, with global manufacturing and qualification infrastructure.

The IRLR series targets automotive-grade discrete power MOSFETs optimized for high-reliability, high-temperature switching in engine, chassis, and body electronics - emphasizing ruggedness, low R_DS(on), and AEC-Q101 compliance.

FAQ

Is IRLR3705Z AEC-Q101 qualified?

Yes, IRLR3705Z is fully AEC-Q101 qualified for automotive applications. Test reports confirm compliance with stress tests including HTGB, HTRB, uHAST, and repetitive avalanche per JEDEC standards. Qualification applies to the D-Pak (TO-252) package variant shipped under this part number.

What is the maximum safe operating frequency for IRLR3705Z in hard-switched applications?

IRLR3705Z supports hard-switched operation up to 500 kHz in well-designed layouts with minimized parasitic inductance. At 200 kHz, total switching loss (E_on + E_off) remains below 1.2 mJ per cycle at 42 A/28 V, assuming RG = 4.2 Ω gate resistor and 12 V gate drive amplitude.

Can IRLR3705Z be used in parallel configurations?

Yes - its positive R_DS(on) temperature coefficient (dR/dT > 0) enables stable current sharing. Parallel operation requires matched gate drive impedance, symmetrical PCB layout, and thermal coupling. Derate total current by 15% versus single-device rating to ensure balanced thermal rise.

Does IRLR3705Z require a gate resistor, and what value is recommended?

A gate resistor is mandatory to control dV/dt and prevent oscillation. For 12 V gate drive and 42 A load, a 4.2 Ω resistor (as specified in Fig. 18a test circuit) provides optimal trade-off between switching speed (t_r/t_f ≈ 150/70 ns) and EMI suppression. Lower values increase ringing risk; higher values raise switching losses.

IRLR3705Z 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:: 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:: Surface Mount

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

IRLR3705Z FAQ

1.How can I place an order for IRLR3705Z through Aetrix?

Please submit a Request for Quotation (RFQ) for IRLR3705Z 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 IRLR3705Z reliable?

The price and inventory of IRLR3705Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IRLR3705Z is usually 5 days.

3.What payment methods are accepted for IRLR3705Z?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IRLR3705Z transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for IRLR3705Z?

IRLR3705Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your IRLR3705Z 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 IRLR3705Z?

For technical support, including IRLR3705Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IRLR3705Z requirements.

6.How does Aetrix verify that IRLR3705Z is sourced from the original manufacturer or authorized distributors?

All IRLR3705Z 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 IRLR3705Z meets industry standards.

7.What is the process for return or replacement of IRLR3705Z?

All IRLR3705Z units undergo pre-shipment inspection (PSI). If there is an issue with IRLR3705Z, 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 IRLR3705Z part is unused and in its original packaging.

Return procedure for IRLR3705Z:

1.Submit a request within 90 days.

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

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