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

Infineon Technologies AUXFN8403TR

Name: AUXFN8403TR
Brand: Infineon Technologies
SKU: AUXFN8403TR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AUXFN8403TR

Manufacturer:: Infineon Technologies

Category:: FETs, MOSFETs

Package:: 8-TQFN Exposed Pad

Datasheet:: AUXFN8403TR.pdf

Description:: MOSFET N-CH 40V 95A 8PQFN

Quantity:: RFQ Add To RFQ list

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Inventory:7,010

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Product details

Overview

AUXFN8403TR from Infineon Technologies (formerly International Rectifier) is an automotive-grade N-channel enhancement-mode Power MOSFET in a PQFN 5 mm × 6 mm package, rated for 40 V V_DSS, 2.5 mΩ R_DS(on) (typ.) at V_GS = 10 V, 122 A silicon-limited continuous drain current, and 175 °C maximum junction temperature. It serves as a high-efficiency main switch in electric power steering (EPS) and battery disconnect circuits.

For engineers reviewing the AUXFN8403TR datasheet, AUXFN8403TR pinout, AUXFN8403TR application, or AUXFN8403TR equivalent, key selection criteria include its 95 A package-limited continuous current, 65 nC typical total gate charge, 1.6 °C/W junction-to-case thermal resistance (bottom side), repetitive avalanche capability up to T_jmax, and AEC-Q101 qualification for under-hood automotive use.

Technical Context

This device employs advanced HEXFET® process technology optimized for low R_DS(on) per die area and robust unclamped inductive switching performance. Its gate threshold voltage (V_GS(th)) ranges from 2.6 V to 3.9 V, enabling reliable turn-on with standard 5 V or 10 V logic-level drivers in high-current DC-DC and load-switching topologies.

The MOSFET integrates a fast, low-loss body diode with 0.9 V typical forward voltage at 50 A and 16 ns reverse recovery time at 25 °C. Its dynamic parameters-including 23 nC Miller charge (Q_gd), 3174 pF input capacitance (C_iss), and 26 ns fall time-support high-frequency synchronous rectification and PWM control up to several hundred kHz.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DSS	40 V - Maximum blocking voltage before avalanche onset; suitable for 12 V/24 V automotive battery systems with transient margin.
R_DS(on) (typ.)	2.5 mΩ @ V_GS = 10 V, I_D = 50 A - Enables <1.25 W conduction loss at 50 A, critical for thermally constrained EPS modules.
I_D (Silicon Limited)	122 A @ T_C = 25 °C - Silicon die capacity; actual usable current limited by package thermal resistance and PCB layout.
Q_g (typ.)	65 nC - Determines gate drive power requirement; enables efficient switching with moderate-strength gate drivers (e.g., 2 A peak).
R_θJC (Bottom)	1.6 °C/W - Thermal path from junction to PCB copper via bottom thermal pad; requires direct solder connection to 2+ oz Cu thermal plane.
E_AS (Tested)	165 mJ - Single-pulse avalanche energy rating; supports robust operation during load dump or inductive kick events without derating.
T_J max	+175 °C - Enables operation in engine bay environments where ambient exceeds 105 °C, with margin for self-heating.

Pinout & Package

PQFN 5 mm × 6 mm Outline "E" package with exposed thermal pad on bottom surface. Pin 1 identifier located at top-left corner of top-side marking; leads are source-connected (S1–S5), drain-connected (D1–D4), and gate-connected (G1) per standard layout.

Pin/Terminal	Circuit Role	Design Meaning
G1	Gate	Single gate terminal; connects to driver IC output; requires low-inductance routing to minimize ringing and overshoot.
D1–D4	Drain	Four parallel drain terminals tied internally to die drain metallization; must be routed to high-current bus or battery rail.
S1–S5	Source	Five parallel source terminals; connect to power ground plane; serve as return path for both MOSFET and body diode current.
Thermal Pad	Drain (internally connected)	Exposed copper pad on bottom surface; must be soldered to large PCB copper area for thermal conduction and mechanical stability.

Key Features

Feature	Design Value
Automotive qualification	AEC-Q101 qualified for automotive applications; validated for temperature cycling, humidity, and mechanical shock per JEDEC standards.
Ultra-low R_DS(on)	2.5 mΩ typ. at 10 V gate drive reduces I²R losses by >30% vs. comparable 40 V MOSFETs, directly improving system efficiency in EPS.
Repetitive avalanche rating	Rated for unlimited repetitive avalanche events up to T_jmax; eliminates need for external snubbers in inductive load switching.
175 °C operation	Enables full-rated performance in under-hood locations where case temperatures reach 150 °C, reducing thermal derating overhead.
Lead-free & RoHS compliant	Meets EU RoHS Directive 2011/65/EU and JEDEC J-STD-020 reflow profile requirements for Pb-free assembly.

Applications

Electric Power Steering (EPS)

Battery Disconnect Switch

Use Scenario: High-current motor phase switching in column-assist or rack-assist EPS modules operating from 12 V battery with peak loads >80 A.

IC Role / Device Role / Timing Role: Main high-side or H-bridge switching element controlling torque motor current direction and magnitude.

Use Value: Low R_DS(on) minimizes heat generation in sealed EPS housing; 175 °C rating ensures reliability across full vehicle lifetime.

Use Scenario: Isolation of 12 V starter battery from auxiliary loads during engine cranking or fault conditions.

IC Role / Device Role / Timing Role: Solid-state replacement for electromechanical contactors; activated via CAN or discrete control signal.

Use Value: Fast turn-off (<60 ns total) prevents backfeed during cranking; avalanche rating handles inductive kick from solenoid coils.

Start/Stop Micro-Hybrid System

48 V–12 V DC-DC Converter

Use Scenario: Bidirectional energy transfer between 12 V battery and start-stop motor/generator in mild hybrid architectures.

IC Role / Device Role / Timing Role: Synchronous rectifier in buck-boost converter stage managing regenerative braking energy recovery.

Use Value: Low Q_gd/Q_g ratio improves light-load efficiency; body diode V_SD < 1.3 V reduces conduction loss during dead-time.

Use Scenario: High-efficiency step-down conversion from 48 V Li-ion traction battery to 12 V auxiliary network in PHEVs.

IC Role / Device Role / Timing Role: Primary switch in synchronous buck topology operating at 200–500 kHz switching frequency.

Use Value: C_iss = 3174 pF and C_oss = 479 pF enable stable zero-voltage switching (ZVS) design; low R_DS(on) sustains >96% efficiency at 60 A output.

Equivalent & Alternatives

The following parts are listed as comparable options for similar N-channel 40 V automotive power MOSFET applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
STL220N4F7AG	R_DS(on) = 1.8 mΩ (lower), Q_g = 95 nC (higher), PQFN 5×6 mm, AEC-Q101 qualified.	Better conduction loss but higher gate drive demand; less suitable for space-constrained EPS modules with weak gate drivers.	Select when thermal budget allows higher gate drive power and lowest possible R_DS(on) is prioritized over switching speed.
ON Semiconductor NTMFS4C09NT1G	R_DS(on) = 3.2 mΩ (higher), Q_g = 52 nC (lower), SO-8FL package, AEC-Q101 qualified.	Lower gate charge eases driver design but higher R_DS(on) increases conduction loss; SO-8FL has higher R_θJA than PQFN.	Select for cost-sensitive non-EPS applications where board space permits larger thermal footprint and 3.2 mΩ is acceptable.

Compared with STL220N4F7AG and NTMFS4C09NT1G, AUXFN8403TR delivers optimal balance of ultra-low R_DS(on), moderate gate charge, and industry-leading thermal resistance-making it preferred for thermally dense, high-reliability automotive power stages where both conduction and switching losses must be minimized.

Availability

AUXFN8403TR is available at Aetrix Electronics and suitable for electric power steering (EPS), battery disconnect switches, and start/stop micro-hybrid systems requiring stable component supply, long-term automotive lifecycle support, and traceable AEC-Q101-compliant sourcing.

Supply support for AUXFN8403TR 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 headquartered in Munich, Germany, specializing in power management, automotive electronics, and sensor solutions with over 50 years of innovation in power semiconductors.

AUXFN8403TR belongs to Infineon's automotive-qualified HEXFET® Power MOSFET product line, engineered specifically for high-current, high-temperature switching in safety-critical vehicle subsystems including steering, braking, and energy management.

FAQ

What is the recommended PCB layout for thermal management of AUXFN8403TR?

The PQFN 5×6 mm package requires a minimum 200 mm² exposed copper thermal pad on the primary PCB layer, connected via ≥6 thermal vias (0.3 mm diameter, filled or capped) to internal ground planes. Application Note AN-1136 specifies 10 mm × 10 mm stencil aperture for the thermal pad and 0.15 mm thickness for optimal solder paste volume. Avoid solder mask over the thermal pad to ensure full thermal contact.

Does AUXFN8403TR support paralleling for higher current applications?

Yes-its positive R_DS(on) temperature coefficient (0.031 V/°C) enables inherent current sharing when multiple devices are paralleled. Designers must match gate drive loop inductance and PCB trace lengths within ±5% to prevent dynamic imbalance. Derate total current by 15% versus sum of individual ratings to account for thermal coupling effects in dense layouts.

What is the maximum allowable dv/dt during body diode commutation?

The datasheet specifies a peak diode recovery dv/dt rating of 2.5 V/ns at T_J = 175 °C and I_S = 50 A. Exceeding this value risks parasitic turn-on of adjacent MOSFETs in half-bridge configurations. Use gate resistors ≥10 Ω and local RC snubbers across drain-source if measured dv/dt exceeds 2.0 V/ns in prototype testing.

How does the repetitive avalanche rating impact system-level protection design?

AUXFN8403TR is rated for unlimited repetitive avalanche events as long as T_j ≤ 175 °C, eliminating need for external avalanche clamps in inductive load circuits. System designers must calculate worst-case avalanche energy per event using E = ½ × 1.3 × V_BR × I_AV × t_AV and verify that cumulative heating stays within thermal limits using Z_thJC curves from Figure 13.

AUXFN8403TR Specifications

Product attributes: Attribute value

Manufacturer:: Infineon Technologies

Series:: HEXFET®

Package/Case:: 8-TQFN Exposed Pad

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

FET Type:: N-Channel

Technology:: MOSFET (Metal Oxide)

Drain to Source Voltage (Vdss):: 40 V

Current - Continuous Drain (Id) @ 25°C:: 95A (Tc)

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

Rds On (Max) @ Id, Vgs:: 3.3mOhm @ 50A, 10V

Vgs(th) (Max) @ Id:: 3.9V @ 100µA

Gate Charge (Qg) (Max) @ Vgs:: 98 nC @ 10 V

Vgs (Max):: ±20V

Input Capacitance (Ciss) (Max) @ Vds:: 3174 pF @ 25 V

FET Feature:: -

Power Dissipation (Max):: 94W (Tc)

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-PQFN (5x6)

AUXFN8403TR FAQ

1.How can I place an order for AUXFN8403TR through Aetrix?

Please submit a Request for Quotation (RFQ) for AUXFN8403TR 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 AUXFN8403TR reliable?

The price and inventory of AUXFN8403TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AUXFN8403TR is usually 5 days.

3.What payment methods are accepted for AUXFN8403TR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AUXFN8403TR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AUXFN8403TR?

AUXFN8403TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AUXFN8403TR 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 AUXFN8403TR?

For technical support, including AUXFN8403TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AUXFN8403TR requirements.

6.How does Aetrix verify that AUXFN8403TR is sourced from the original manufacturer or authorized distributors?

All AUXFN8403TR 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 AUXFN8403TR meets industry standards.

7.What is the process for return or replacement of AUXFN8403TR?

All AUXFN8403TR units undergo pre-shipment inspection (PSI). If there is an issue with AUXFN8403TR, 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 AUXFN8403TR part is unused and in its original packaging.

Return procedure for AUXFN8403TR:

1.Submit a request within 90 days.

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

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