FDB8442 Equivalent & Substitute Parts

Part Overview

The FDB8442 is an N-Channel MOSFET manufactured by onsemi, rated for 40V drain-to-source voltage with continuous drain current of 28A (Ta) and 80A (Tc). The device is housed in a Surface Mount TO-263 (D2PAK) package and is part of the PowerTrench® series. The FDB8442 is classified as obsolete, making identification of equivalent and substitute parts necessary for ongoing design support and procurement continuity. Substitute parts must maintain electrical compatibility across voltage ratings, current handling, thermal characteristics, and package form factors while meeting or exceeding the performance envelope of the original device.

Substiute Parts

FDB8442

onsemiIn Stock: 2385FDB8442 Datasheet

Current PartRFQ

BUK765R2-40B,118

NXP USA Inc.In Stock: 24087BUK765R2-40B,118 Datasheet

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IXTA220N04T2-7

IXYSIn Stock: 1035IXTA220N04T2-7 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the FDB8442 is determined by strict adherence to the following electrical and mechanical parameters:

Primary Substitution Criteria:

• Drain-to-Source Voltage (Vdss): Must equal or exceed 40V
• Continuous Drain Current (Id): Must meet or exceed 80A (Tc) rating
• Gate Threshold Voltage (Vgs(th)): Must be compatible at 4V nominal
• Maximum Gate Voltage (Vgs Max): Must support ±20V operation
• Operating Temperature Range: Must span -55°C to 175°C (TJ)
• Package Type: Must be Surface Mount D2PAK or compatible TO-263 variant
• FET Technology: N-Channel MOSFET (Metal Oxide)

Secondary Compatibility Parameters:

• On-State Resistance (Rds On): Lower values indicate improved performance
• Gate Charge (Qg): Lower values reduce switching losses
• Input Capacitance (Ciss): Lower values reduce gate drive requirements
• Power Dissipation: Higher ratings provide thermal margin

The two substitute parts listed below satisfy all primary criteria and provide enhanced performance in secondary parameters.

Parameter Comparison

Engineering Selection Recommendations

BUK765R2-40B,118 (NXP USA Inc.):

This substitute is an active product classified as automotive-grade with AEC-Q101 qualification. The device meets all primary substitution criteria with a 40V Vdss rating and 75A (Tc) continuous drain current. While the continuous drain current is slightly below the FDB8442's 80A (Tc) rating, the part remains functionally compatible for applications where the 75A rating is acceptable. The BUK765R2-40B,118 exhibits superior gate charge characteristics (52 nC versus 235 nC) and significantly lower input capacitance (3789 pF versus 12200 pF), resulting in reduced switching losses and improved gate drive efficiency. The automotive qualification and active product status provide long-term supply assurance. Package compatibility is confirmed as D2PAK Surface Mount.

IXTA220N04T2-7 (IXYS):

This substitute is an active product with RoHS3 compliance and MSL 1 rating. The device exceeds all primary substitution criteria with a 40V Vdss rating and 220A (Tc) continuous drain current, providing substantial thermal and current margin over the FDB8442. The IXTA220N04T2-7 demonstrates improved on-state resistance (3.5 mOhm versus 2.9 mOhm at different measurement points) and lower gate charge (112 nC versus 235 nC), enabling reduced power dissipation in switching applications. Power dissipation capability is enhanced at 360W (Tc) versus 254W (Tc). The operating temperature range and maximum gate voltage specifications are identical to the FDB8442. Package form is TO-263-7 (IXTA) Surface Mount, which is a variant of the D2PAK family. This part is suitable for applications requiring higher current capacity and thermal performance.

Both substitute parts maintain compatibility with the FDB8442 across all critical electrical parameters and operating conditions. Selection between them depends on application-specific requirements for current capacity, thermal dissipation, and gate drive characteristics.

Frequently Asked Questions (FAQ)

Q: Can the BUK765R2-40B,118 be used as a direct replacement for the FDB8442?

A: The BUK765R2-40B,118 meets all primary electrical substitution criteria including 40V Vdss, ±20V gate voltage, and -55°C to 175°C operating temperature. The continuous drain current rating of 75A (Tc) is slightly below the FDB8442's 80A (Tc). Direct substitution is possible for applications where the 75A rating satisfies design requirements. Both devices use D2PAK Surface Mount packaging. Verification of current requirements in the specific application is necessary before implementation.

Q: What are the key differences between the IXTA220N04T2-7 and the FDB8442?

A: The IXTA220N04T2-7 provides significantly higher continuous drain current (220A Tc versus 80A Tc) and power dissipation capability (360W versus 254W). Both devices share identical 40V Vdss ratings, ±20V gate voltage limits, and -55°C to 175°C operating temperature ranges. The IXTA220N04T2-7 uses a TO-263-7 (IXTA) package variant with six leads plus tab, compared to the FDB8442's standard D2PAK configuration. Gate charge is lower in the IXTA220N04T2-7 (112 nC versus 235 nC), reducing switching losses. The IXTA220N04T2-7 is suitable for high-current applications requiring enhanced thermal performance.

Q: Are there package compatibility concerns when substituting these parts?

A: The FDB8442 uses TO-263 (D2PAK) Surface Mount packaging. The BUK765R2-40B,118 uses standard D2PAK packaging, which is directly compatible. The IXTA220N04T2-7 uses TO-263-7 (IXTA) packaging, which is a variant of the D2PAK family with additional leads. PCB layout modifications may be required for the IXTA220N04T2-7 due to the different pin configuration. Verification of footprint compatibility with the target PCB design is required before implementation.

Q: What is the significance of the gate charge difference between these parts?

A: Gate charge (Qg) determines the energy required to switch the MOSFET on and off. The FDB8442 has a gate charge of 235 nC at 10V, while the BUK765R2-40B,118 has 52 nC and the IXTA220N04T2-7 has 112 nC. Lower gate charge reduces switching losses and allows for faster switching speeds with lower gate drive power requirements. The BUK765R2-40B,118 offers the lowest gate charge, making it advantageous for high-frequency switching applications. The IXTA220N04T2-7 provides intermediate gate charge with higher current capacity.

Q: How do the on-state resistance specifications compare?

A: On-state resistance (Rds On) directly affects conduction losses and heat generation. The FDB8442 specifies 2.9 mOhm at 80A and 10V gate voltage. The BUK765R2-40B,118 specifies 5.2 mOhm at 25A and 10V gate voltage, and the IXTA220N04T2-7 specifies 3.5 mOhm at 50A and 10V gate voltage. Direct comparison is limited due to different measurement conditions. The IXTA220N04T2-7 demonstrates favorable on-state resistance characteristics at higher current levels, supporting its suitability for high-current applications.

Q: What product status considerations apply to these substitutes?

A: The FDB8442 is classified as obsolete, necessitating the use of alternative parts. Both substitute parts are active products with ongoing manufacturer support. The BUK765R2-40B,118 carries automotive-grade qualification (AEC-Q101), providing additional assurance for long-term availability and quality standards. The IXTA220N04T2-7 is RoHS3 compliant, meeting environmental regulatory requirements. Active product status ensures continued supply availability and technical support for both substitutes.

Q: Are there thermal performance differences between these parts?

A: Maximum power dissipation ratings indicate thermal performance capability. The FDB8442 is rated for 254W (Tc), the BUK765R2-40B,118 for 203W (Tc), and the IXTA220N04T2-7 for 360W (Tc). The IXTA220N04T2-7 provides the highest thermal margin, making it suitable for applications with elevated ambient temperatures or high switching frequencies. The BUK765R2-40B,118 has lower power dissipation capability but compensates with reduced gate charge and input capacitance, resulting in lower switching losses in many applications.