IRFS7437PBF N-Channel MOSFET 40V 195A Equivalent & Substitute Parts

Part Overview

The IRFS7437PBF is an N-Channel MOSFET manufactured by Infineon Technologies, rated for 40V drain-to-source voltage with 195A continuous drain current at 25°C. This device is housed in a D2PAK (TO-263-3) surface mount package and is designed for high-current switching applications requiring low on-resistance performance. The part is currently discontinued at DiGi Electronics, making identification of equivalent substitute components essential for ongoing design support and production continuity.

Substiute Parts

IRFS7437PBF

Infineon TechnologiesIn Stock: 5347IRFS7437PBF Datasheet

Current PartRFQ

FDB9406-F085

onsemiIn Stock: 2908FDB9406-F085 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the IRFS7437PBF is determined by strict alignment of the following electrical and mechanical parameters:

Primary Substitution Criteria:

• FET Type: N-Channel topology
• Drain to Source Voltage (Vdss): 40V minimum rating
• Package: TO-263-3 or D2PAK (2 Leads + Tab) surface mount
• Mounting Type: Surface Mount
• RoHS Compliance: ROHS3 Compliant

Secondary Compatibility Parameters:

• Continuous Drain Current (Id): Minimum 110A at 25°C
• On-Resistance (Rds On): Maximum 1.8 mOhm at specified gate voltage
• Operating Temperature Range: -55°C to 175°C minimum
• Gate Charge (Qg): Electrical compatibility within switching circuit design

The FDB9406-F085 manufactured by onsemi meets all primary substitution criteria. This part shares identical voltage rating, package configuration, and compliance standards. While the continuous drain current rating is lower at 110A compared to the IRFS7437PBF's 195A, the on-resistance specification of 1.8 mOhm at 10V gate voltage and power dissipation rating of 176W provide functional equivalence for applications within the FDB9406-F085's current envelope.

Parameter Comparison

Engineering Selection Recommendations

Substitution Feasibility:

The FDB9406-F085 is a direct substitute for the IRFS7437PBF within the constraints of its electrical ratings. Both devices are ROHS3 compliant and operate across the identical temperature range of -55°C to 175°C. The D2PAK package configuration is mechanically and electrically compatible, requiring no PCB layout modifications.

Current Rating Consideration:

The primary design parameter difference is the continuous drain current rating. The IRFS7437PBF is rated for 195A at 25°C, while the FDB9406-F085 is rated for 110A at 25°C. Substitution is appropriate only for applications where the actual operating drain current does not exceed 110A. Applications requiring the full 195A capability of the IRFS7437PBF cannot use the FDB9406-F085 as a direct substitute.

Compliance and Qualification:

The FDB9406-F085 carries AEC-Q101 automotive qualification, providing additional reliability assurance for applications requiring automotive-grade components. Both parts maintain REACH compliance and EAR99 export classification.

Gate Charge and Switching Performance:

The FDB9406-F085 exhibits lower gate charge (138 nC versus 225 nC at 10V), resulting in faster switching transitions and reduced gate drive power requirements. This characteristic may provide secondary benefits in high-frequency switching applications.

Frequently Asked Questions (FAQ)

Q: Can the FDB9406-F085 be used as a direct pin-for-pin replacement for the IRFS7437PBF?

A: Yes, the FDB9406-F085 is a direct pin-for-pin replacement in the D2PAK package. Both devices use identical TO-263-3 pinout with no modifications required to PCB layout or gate drive circuitry.

Q: What is the primary limitation when substituting the FDB9406-F085 for the IRFS7437PBF?

A: The continuous drain current rating is lower. The FDB9406-F085 is rated for 110A at 25°C compared to the IRFS7437PBF's 195A. Substitution is valid only when actual circuit drain current remains below 110A.

Q: Are there thermal management differences between these two devices?

A: Yes. The IRFS7437PBF has a maximum power dissipation of 230W (Tc), while the FDB9406-F085 is rated for 176W (Tj). Thermal design calculations must account for this 54W difference in maximum dissipation capability.

Q: Do both devices require identical gate drive voltage?

A: Both devices specify 10V as the drive voltage for maximum on-resistance performance. Gate threshold voltages are similar (3.9V for IRFS7437PBF, 4V for FDB9406-F085), ensuring compatible gate drive circuit design.

Q: What is the significance of the lower gate charge in the FDB9406-F085?

A: The FDB9406-F085 exhibits 138 nC gate charge versus 225 nC for the IRFS7437PBF at 10V. Lower gate charge reduces gate drive power consumption and enables faster switching transitions, which may improve efficiency in high-frequency applications.

Q: Are both devices suitable for automotive applications?

A: The FDB9406-F085 carries AEC-Q101 automotive qualification. The IRFS7437PBF does not list automotive qualification in the provided specifications. For automotive applications, the FDB9406-F085 provides documented qualification compliance.

Q: What is the moisture sensitivity level for both devices?

A: Both the IRFS7437PBF and FDB9406-F085 are rated MSL 1 (Unlimited), indicating no moisture sensitivity restrictions during storage or handling.

Q: Can the FDB9406-F085 be used in applications requiring 195A continuous current?

A: No. The FDB9406-F085 is rated for maximum 110A continuous drain current at 25°C. Using this device in applications requiring 195A operation will result in thermal stress and potential device failure.