IRFS7440PBF N-Channel 40V 120A MOSFET Equivalent & Substitute Parts

Part Overview

The IRFS7440PBF is an N-Channel MOSFET manufactured by Infineon Technologies, rated for 40V drain-to-source voltage with 120A continuous drain current at 25°C. This device is packaged in TO-263 (D2PAK) surface mount configuration and is designed for high-current switching applications. The part is discontinued at DiGi Electronics, making identification of equivalent and substitute components essential for ongoing design support and production continuity. Substitute parts must maintain compatibility across voltage rating, current handling capability, package type, and thermal performance parameters.

Key Parameters

Parameter	Value	Unit
FET Type	N-Channel	—
Drain to Source Voltage (Vdss)	40	V
Current - Continuous Drain (Id) @ 25°C	120	A
Rds On (Max) @ Id, Vgs	2.5 mOhm @ 100A, 10V	—
Power Dissipation (Max)	208	W
Operating Temperature Range	-55 to 175	°C
Mounting Type	Surface Mount	—
Package / Case	TO-263-3, D2PAK	—
RoHS Status	ROHS3 Compliant	—

Substitute Part Grouping Explanation

Substitution of the IRFS7440PBF is determined by strict adherence to the following electrical and mechanical parameters:

Critical Substitution Criteria:

Drain to Source Voltage (Vdss): Must equal 40V
FET Type: Must be N-Channel
Package Type: Must be TO-263 (D2PAK) surface mount
Operating Temperature Range: Must support -55°C to 175°C
RoHS Compliance: Must maintain ROHS3 Compliant status

Current and Power Handling: Substitute parts may have equal or greater continuous drain current (Id) and power dissipation ratings. Parts with lower current or power ratings are not suitable substitutes.

On-Resistance (Rds On): Substitute parts must maintain electrical performance within acceptable limits for the application. Lower Rds On values indicate improved performance.

The two substitute parts identified—STB120N4F6 and STB270N4F3—both meet the voltage, package, and compliance requirements. They differ in current handling capacity and thermal performance, allowing selection based on specific application requirements.

Parameter Comparison

Parameter	IRFS7440PBF (Main)	STB120N4F6 (Substitute)	STB270N4F3 (Substitute)
Manufacturer	Infineon Technologies	STMicroelectronics	STMicroelectronics
FET Type	N-Channel	N-Channel	N-Channel
Vdss	40 V	40 V	40 V
Id @ 25°C	120 A	80 A	160 A
Rds On (Max)	2.5 mOhm @ 100A, 10V	4 mOhm @ 40A, 10V	2.5 mOhm @ 80A, 10V
Power Dissipation (Max)	208 W	110 W	330 W
Operating Temperature	-55 to 175 °C	-55 to 175 °C	-55 to 175 °C
Package / Case	TO-263-3, D2PAK	TO-263-3, D2PAK	TO-263-3, D2PAK
Product Status	Discontinued	Active	Active
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
AEC-Q101 Qualification	Not specified	Yes	Yes

Engineering Selection Recommendations

STB120N4F6 Selection Criteria: The STB120N4F6 is suitable for applications where the IRFS7440PBF current rating of 120A exceeds system requirements. This substitute provides 80A continuous drain current with lower power dissipation (110W). The part is actively manufactured by STMicroelectronics and carries AEC-Q101 automotive qualification. ROHS3 compliance is maintained. Use this substitute when design margins permit operation at 80A or lower continuous current levels.

STB270N4F3 Selection Criteria: The STB270N4F3 is suitable for applications requiring performance equal to or exceeding the IRFS7440PBF specifications. This substitute provides 160A continuous drain current and 330W power dissipation, both exceeding the original part. On-resistance matches the original specification at 2.5 mOhm. The part is actively manufactured by STMicroelectronics and carries AEC-Q101 automotive qualification. ROHS3 compliance is maintained. Use this substitute for direct replacement or when higher current capacity is beneficial.

Both substitutes maintain the TO-263 (D2PAK) package footprint, operating temperature range, and voltage rating of the original IRFS7440PBF. Selection between substitutes depends on application current requirements and thermal management capabilities.

Frequently Asked Questions (FAQ)

Q: Can STB120N4F6 be used as a direct replacement for IRFS7440PBF? A: STB120N4F6 is electrically compatible but has lower current rating (80A vs. 120A) and power dissipation (110W vs. 208W). It is suitable only if application current requirements do not exceed 80A continuous drain current.

Q: Can STB270N4F3 be used as a direct replacement for IRFS7440PBF? A: Yes. STB270N4F3 meets or exceeds all electrical specifications of IRFS7440PBF, including current rating (160A vs. 120A), power dissipation (330W vs. 208W), and on-resistance (2.5 mOhm). Package and voltage ratings are identical.

Q: Are both substitutes in the same package as the original part? A: Yes. Both STB120N4F6 and STB270N4F3 use TO-263-3 (D2PAK) surface mount packaging, identical to IRFS7440PBF. PCB footprint compatibility is maintained.

Q: What is the difference in on-resistance between the substitutes? A: STB120N4F6 has 4 mOhm maximum on-resistance at 40A, 10V. STB270N4F3 has 2.5 mOhm maximum on-resistance at 80A, 10V. Lower on-resistance reduces power dissipation and heat generation.

Q: Do the substitute parts have automotive qualification? A: Both STB120N4F6 and STB270N4F3 carry AEC-Q101 automotive qualification. IRFS7440PBF qualification status is not specified in available data.

Q: Are the substitute parts RoHS compliant? A: Yes. Both STB120N4F6 and STB270N4F3 are ROHS3 compliant, matching the original IRFS7440PBF compliance status.

Q: What is the product availability status of the substitutes? A: Both STB120N4F6 and STB270N4F3 are active products manufactured by STMicroelectronics. IRFS7440PBF is discontinued at DiGi Electronics.

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