FDD8770 N-Channel MOSFET Equivalent & Substitute Parts

Part Overview

The FDD8770 is an N-Channel MOSFET manufactured by onsemi, rated for 25V drain-to-source voltage with 35A continuous drain current at 25°C. The device is housed in a TO-252AA (DPAK) surface mount package and delivers 115W maximum power dissipation. The FDD8770 is classified as obsolete, necessitating identification of active equivalent and substitute components for new designs and production continuity. Substitute parts must maintain electrical compatibility within the specified voltage and current parameters while accommodating the same or compatible package footprints.

Substiute Parts

FDD8770

onsemiIn Stock: 30177FDD8770 Datasheet

Current PartRFQ

NVD4C05NT4G

onsemiIn Stock: 878NVD4C05NT4G Datasheet

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AOD424

Alpha & Omega Semiconductor Inc.In Stock: 17708AOD424 Datasheet

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PJD85N03_L2_00001

Panjit International Inc.In Stock: 5496PJD85N03_L2_00001 Datasheet

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STD17NF03LT4

STMicroelectronicsIn Stock: 8802STD17NF03LT4 Datasheet

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STD95N2LH5

STMicroelectronicsIn Stock: 17829STD95N2LH5 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the FDD8770 is determined by the following critical parameters:

Voltage Rating (Vdss): Substitute parts must have a Vdss rating equal to or greater than 25V. Parts rated at 30V provide additional voltage margin and are acceptable for applications operating at or below 25V.

Continuous Drain Current (Id): Substitute parts must support the required continuous drain current. The FDD8770 specifies 35A at 25°C (Tc). Substitute parts with equal or higher current ratings are acceptable.

On-Resistance (Rds On): The FDD8770 exhibits 4 mOhm maximum at 35A and 10V gate-source voltage. Substitute parts with comparable or lower on-resistance values maintain thermal performance and power efficiency.

Package Compatibility: All substitute parts must use the TO-252-3 (DPAK) surface mount package to ensure PCB footprint compatibility without layout redesign.

Operating Temperature Range: The FDD8770 operates from -55°C to 175°C. Substitute parts must support this full range or a compatible subset.

Compliance Status: All substitute parts must maintain RoHS3 compliance and REACH unaffected status to satisfy regulatory requirements.

The following substitute parts meet these criteria and are grouped by their suitability for direct replacement:

Manufacturer-Recommended Substitute: NVD4C05NT4G (onsemi) — Active status, automotive qualified, higher voltage and current ratings.

Similar Substitutes: AOD424, PJD85N03_L2_00001, STD17NF03LT4, STD95N2LH5 — All active status, TO-252 package, varying voltage and current specifications.

Parameter Comparison

Engineering Selection Recommendations

NVD4C05NT4G (onsemi) is the manufacturer-recommended substitute. This part is manufactured by onsemi, the original FDD8770 manufacturer, ensuring design continuity and process consistency. The NVD4C05NT4G carries active product status and holds AEC-Q101 automotive qualification, providing enhanced reliability assurance. With a 30V Vdss rating and 90A continuous drain current (Tc), this device exceeds the FDD8770 specifications and is suitable for direct replacement in applications requiring 25V operation. The 4.1 mOhm on-resistance at 45A and 10V gate-source voltage maintains thermal performance comparable to the original part.

STD95N2LH5 (STMicroelectronics) provides the closest electrical match to the FDD8770. Both devices are rated for 25V Vdss, and the STD95N2LH5 delivers 80A continuous drain current (Tc), significantly exceeding the FDD8770's 35A specification. The on-resistance of 4.5 mOhm at 40A and 10V is nearly equivalent to the original part. This device is active, RoHS3 compliant, and operates across the full -55°C to 175°C temperature range. The STD95N2LH5 is part of the STripFET™ V series and is suitable for applications where voltage and current headroom are beneficial.

AOD424 (Alpha & Omega Semiconductor Inc.) is an active alternative with a 20V Vdss rating and 45A continuous drain current (Tc). This part operates within the FDD8770's voltage envelope and provides current capability exceeding the original specification. The 4.4 mOhm on-resistance at 20A and 4.5V gate-source voltage is comparable to the FDD8770. The AOD424 is RoHS3 compliant and operates across -55°C to 175°C. This device is suitable for applications where 20V operation is acceptable and cost optimization is a consideration.

PJD85N03_L2_00001 (Panjit International Inc.) is an active part rated for 30V Vdss and 85A continuous drain current (Tc). The on-resistance of 3.8 mOhm at 20A and 10V is superior to the FDD8770. This device is RoHS3 compliant but operates only to 150°C maximum junction temperature, which is 25°C below the FDD8770 specification. This part is suitable for applications where the reduced upper temperature limit does not conflict with system requirements.

STD17NF03LT4 (STMicroelectronics) is an active part rated for 30V Vdss and 17A continuous drain current (Tc). The on-resistance of 50 mOhm at 8.5A and 10V is significantly higher than the FDD8770, resulting in reduced current-handling capability and increased thermal dissipation. This device is part of the STripFET™ II series and is suitable only for applications where lower current requirements permit the use of a higher on-resistance device. The STD17NF03LT4 is RoHS3 compliant and operates across -55°C to 175°C.

All substitute parts maintain RoHS3 compliance, REACH unaffected status, and MSL 1 (Unlimited) moisture sensitivity classification, ensuring compatibility with standard manufacturing and storage practices.

Frequently Asked Questions (FAQ)

Q: Can the NVD4C05NT4G directly replace the FDD8770 without circuit modification?

A: Yes. The NVD4C05NT4G is the manufacturer-recommended substitute and shares the same TO-252-3 (DPAK) package footprint. The 30V Vdss rating provides voltage margin for 25V applications, and the 90A continuous drain current (Tc) exceeds the FDD8770's 35A specification. No circuit modifications are required for direct substitution.

Q: What is the primary difference between the NVD4C05NT4G and STD95N2LH5?

A: Both devices are suitable substitutes, but they originate from different manufacturers. The NVD4C05NT4G is manufactured by onsemi (the FDD8770 original manufacturer) and carries AEC-Q101 automotive qualification. The STD95N2LH5 is manufactured by STMicroelectronics and is part of the STripFET™ V series. Both are rated for 25V Vdss and deliver comparable on-resistance performance. Selection depends on supply chain availability and qualification requirements.

Q: Why does the AOD424 have a lower Vdss rating (20V) than the FDD8770 (25V)?

A: The AOD424 is rated for 20V Vdss, which is lower than the FDD8770's 25V specification. This device is suitable only for applications where the maximum operating voltage does not exceed 20V. For circuits designed to operate at 25V, the AOD424 is not an appropriate substitute.

Q: Is the PJD85N03_L2_00001 suitable for high-temperature applications?

A: The PJD85N03_L2_00001 operates to a maximum junction temperature of 150°C, which is 25°C below the FDD8770's 175°C specification. This device is not suitable for applications requiring operation above 150°C. For high-temperature applications, select NVD4C05NT4G, STD95N2LH5, AOD424, or STD17NF03LT4, all of which support 175°C operation.

Q: What does the on-resistance (Rds On) parameter indicate for substitution purposes?

A: On-resistance determines the voltage drop across the device during conduction and directly affects power dissipation and thermal performance. Lower on-resistance values result in reduced heat generation. The FDD8770 specifies 4 mOhm at 35A and 10V. Substitute parts with equal or lower on-resistance values maintain or improve thermal efficiency. The STD17NF03LT4's 50 mOhm on-resistance is significantly higher and results in substantially increased power dissipation.

Q: Are all substitute parts available in the same packaging as the FDD8770?

A: Yes. All substitute parts listed are housed in the TO-252-3 (DPAK) surface mount package, which is identical to the FDD8770 package. PCB footprints are compatible without modification.

Q: What compliance certifications are relevant for substitute part selection?

A: All substitute parts maintain RoHS3 compliance and REACH unaffected status, matching the FDD8770 regulatory classification. The NVD4C05NT4G additionally carries AEC-Q101 automotive qualification, which is relevant for automotive applications. All parts have MSL 1 (Unlimited) moisture sensitivity classification, permitting standard manufacturing and storage practices.

Q: Can the STD17NF03LT4 be used in high-current applications?

A: No. The STD17NF03LT4 is rated for only 17A continuous drain current (Tc), which is significantly below the FDD8770's 35A specification. Additionally, its 50 mOhm on-resistance is substantially higher than the FDD8770, resulting in excessive power dissipation in high-current circuits. This device is suitable only for low-current applications.

Q: What is the significance of the "Tc" and "Ta" designations in current ratings?

A: "Tc" denotes continuous drain current at case temperature (typically 25°C), while "Ta" denotes continuous drain current at ambient temperature. Tc ratings are generally higher than Ta ratings because case temperature is typically lower than ambient temperature in thermal management scenarios. For substitution purposes, compare Tc ratings when both are available.