FDMC7678 N-Channel MOSFET Equivalent & Substitute Parts

Part Overview

The FDMC7678 is an N-Channel 30V MOSFET manufactured by onsemi, rated for 17.5A continuous drain current (Ta) and 19.5A (Tc) in a surface mount 8-MLP (3.3x3.3) package. This device is part of the PowerTrench® series and is classified as obsolete. Due to its obsolete status, equivalent and substitute parts are necessary for ongoing design support, production continuity, and new application development. Suitable alternatives maintain the core electrical specifications while offering active product status or improved performance characteristics.

Substiute Parts

FDMC7678

onsemiIn Stock: 35422FDMC7678 Datasheet

Current PartRFQ

NTTFS4C06NTAG

onsemiIn Stock: 65245NTTFS4C06NTAG Datasheet

MFR RecommendedRFQ

FDMC7678-L701

onsemiIn Stock: 6890FDMC7678-L701 Datasheet

Parametric EquivalentRFQ

AON7530

Alpha & Omega Semiconductor Inc.In Stock: 19428AON7530 Datasheet

SimilarRFQ

AON7534

Alpha & Omega Semiconductor Inc.In Stock: 250307AON7534 Datasheet

SimilarRFQ

CSD17577Q3AT

Texas InstrumentsIn Stock: 16850CSD17577Q3AT Datasheet

SimilarRFQ

DMN3008SFG-13

Diodes IncorporatedIn Stock: 2963DMN3008SFG-13 Datasheet

SimilarRFQ

DMN3008SFG-7

Diodes IncorporatedIn Stock: 101378DMN3008SFG-7 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the FDMC7678 is determined by the following critical parameters:

Electrical Compatibility Criteria:

• Drain to Source Voltage (Vdss): Must equal or exceed 30V
• Continuous Drain Current: Must support minimum 17.5A (Ta) operation
• Gate Threshold Voltage (Vgs(th)): Must be compatible with 10V gate drive
• Rds On: Lower or equivalent values ensure thermal performance
• Operating Temperature Range: Must span -55°C to 150°C

Mechanical Compatibility Criteria:

• Mounting Type: Surface mount only
• Package footprint compatibility: 8-pin configurations with similar thermal characteristics
• Moisture Sensitivity Level: MSL 1 (Unlimited) preferred for handling consistency

Regulatory Compliance:

• RoHS3 compliance required
• REACH unaffected status maintained

Substitute parts are grouped into three categories:

1. Parametric Equivalent (FDMC7678-L701): Identical electrical specifications with active product status and alternative packaging format (Tape & Reel).

2. Manufacturer Recommended (NTTFS4C06NTAG): onsemi alternative with 30V Vdss, active status, and enhanced thermal performance at Tc rating (67A), though lower Ta rating (11A).

3. Similar Performance Alternatives (AON7530, AON7534, CSD17577Q3AT, DMN3008SFG-13, DMN3008SFG-7): Cross-manufacturer options meeting 30V Vdss and 17.5A+ continuous current requirements with varying package types and thermal ratings.

Parameter Comparison

Engineering Selection Recommendations

First Choice: FDMC7678-L701

FDMC7678-L701 is the parametric equivalent with identical electrical specifications (17.5A Ta, 19.5A Tc, 5.3 mOhm Rds On). This part maintains the same PowerTrench® series characteristics and is manufactured by onsemi. Product status is active, ensuring long-term availability. The primary difference is packaging format (Tape & Reel versus Cut Tape). This part is suitable for direct replacement in existing designs with no electrical re-qualification required.

Second Choice: NTTFS4C06NTAG

NTTFS4C06NTAG is the manufacturer-recommended onsemi alternative. It maintains 30V Vdss and active product status. The part exhibits superior Rds On performance (4.2 mOhm @ 30A) and lower gate threshold voltage (2.2V). However, the Ta rating is reduced to 11A, which may limit suitability for applications requiring the full 17.5A continuous current at ambient temperature. The Tc rating of 67A indicates enhanced thermal performance under case temperature conditions. This part is suitable for applications where case temperature operation is primary and ambient temperature current requirements are lower.

Third Choice: CSD17577Q3AT

CSD17577Q3AT is a Texas Instruments NexFET™ series device with 30V Vdss and 35A Ta rating, exceeding FDMC7678 current capability. Product status is active. Rds On is 4.8 mOhm @ 16A, and gate threshold voltage is 1.8V, indicating lower gate drive requirements. Power dissipation at Ta is 2.8W, comparable to FDMC7678. Package is 8-VSONP (3x3.3), which differs from the original 8-MLP footprint and requires PCB layout verification. This part is suitable for applications requiring higher current capability with active product support.

Fourth Choice: AON7530

AON7530 is an Alpha & Omega Semiconductor device with 30V Vdss and 24A Ta rating. Product status is active. Rds On is 4.7 mOhm @ 20A, and gate threshold voltage is 2.2V. Power dissipation is 24W (Ta only). Package is 8-DFN-EP (3x3), requiring PCB layout verification. This part is suitable for applications where higher current capability is beneficial and package footprint change is acceptable.

Fifth Choice: DMN3008SFG-7 or DMN3008SFG-13

Both Diodes Incorporated parts (DMN3008SFG-7 and DMN3008SFG-13) provide 30V Vdss and 17.6A Ta rating, closely matching FDMC7678 current specifications. Product status is active for both variants. Rds On is 4.6 mOhm @ 13.5A. Gate charge is significantly higher at 86 nC @ 10V compared to FDMC7678 at 39 nC, indicating increased switching losses. Input capacitance is also higher at 3690 pF. Package is PowerDI3333-8, requiring PCB layout verification. These parts are suitable for applications where current matching is critical and switching frequency is not a primary concern.

Not Recommended: AON7534

AON7534 has product status "Not For New Designs," which disqualifies it from new application development despite meeting electrical specifications.

Frequently Asked Questions (FAQ)

Q: Can FDMC7678-L701 be used as a direct replacement for FDMC7678?

A: Yes. FDMC7678-L701 is a parametric equivalent with identical electrical specifications and the same PowerTrench® series design. The only difference is packaging format (Tape & Reel versus Cut Tape). No electrical re-qualification is required. PCB layout remains unchanged.

Q: What is the primary limitation of NTTFS4C06NTAG as a substitute?

A: NTTFS4C06NTAG has a reduced Ta (ambient temperature) rating of 11A compared to FDMC7678 at 17.5A. This part is suitable only for applications where the device operates primarily under case temperature conditions or where continuous ambient temperature current requirements are below 11A. For applications requiring full 17.5A at ambient temperature, this part is not suitable.

Q: Why do DMN3008SFG-7 and DMN3008SFG-13 have higher gate charge than FDMC7678?

A: Gate charge (Qg) is a device-specific characteristic determined by the internal gate structure and capacitance. DMN3008SFG parts have Qg of 86 nC @ 10V versus FDMC7678 at 39 nC @ 10V. Higher gate charge results in increased switching losses and slower switching speed. This affects applications with high switching frequency or tight timing requirements.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All substitute parts listed are RoHS3 compliant, matching the compliance status of FDMC7678. All parts also maintain REACH unaffected status.

Q: What is the significance of package type differences?

A: FDMC7678 uses 8-MLP (3.3x3.3) package. Substitute parts use alternative packages such as 8-WDFN, 8-DFN-EP, 8-VSONP, and PowerDI3333-8. While all are surface mount 8-pin configurations with similar thermal characteristics, PCB footprint, trace routing, and thermal via placement differ. PCB layout verification is required when changing package types.

Q: Which substitute part has the lowest Rds On?

A: NTTFS4C06NTAG has the lowest Rds On at 4.2 mOhm @ 30A, followed by CSD17577Q3AT at 4.8 mOhm @ 16A and AON7530 at 4.7 mOhm @ 20A. Lower Rds On reduces conduction losses and heat generation. However, Rds On values are measured at different current levels, so direct comparison requires normalization to the same operating current.

Q: Is FDMC7678-L701 available in the same packaging format as FDMC7678?

A: FDMC7678-L701 uses the same 8-MLP (3.3x3.3) package as FDMC7678. The difference is supply format: FDMC7678 is supplied in Cut Tape (CT) & Digi-Reel®, while FDMC7678-L701 is supplied in Tape & Reel (TR). Both are compatible with automated assembly equipment.

Q: What is the operating temperature range for all substitute parts?

A: All substitute parts maintain the -55°C to 150°C (TJ) operating temperature range, matching FDMC7678. This ensures thermal performance consistency across the full operating envelope.

Q: Why is AON7534 listed as "Not For New Designs"?

A: AON7534 has product status "Not For New Designs," indicating that the manufacturer recommends against using this part in new applications. While it meets electrical specifications, this status reflects the manufacturer's product lifecycle strategy. For new designs, select from parts with "Active" status: FDMC7678-L701, NTTFS4C06NTAG, AON7530, CSD17577Q3AT, DMN3008SFG-13, or DMN3008SFG-7.

Q: What is Moisture Sensitivity Level (MSL) and why does it matter?

A: MSL indicates the maximum time a component can be exposed to ambient conditions (typically 30°C, 85% relative humidity) before soldering. MSL 1 (Unlimited) means the part has no time restriction and can be stored indefinitely under standard conditions. FDMC7678 and most substitute parts have MSL 1, ensuring consistent handling and storage requirements.