FDS6984S Equivalent & Substitute Parts

Part Overview

The FDS6984S is a dual N-channel MOSFET array manufactured by onsemi, designed for surface mount applications in the 8-SOIC package. This device features a 30V drain-to-source voltage rating with continuous drain current capabilities of 5.5A and 8.5A, and is rated for 900mW maximum power dissipation. The FDS6984S operates across a temperature range of -55°C to 150°C and incorporates Logic Level Gate technology for direct digital interface compatibility.

The FDS6984S is classified as an obsolete product. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production requirements for applications currently utilizing this component.

Substiute Parts

FDS6984S

onsemiIn Stock: 7879FDS6984S Datasheet

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FDS6986AS

Fairchild SemiconductorIn Stock: 50378FDS6986AS Datasheet

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DMG4822SSD-13

Diodes IncorporatedIn Stock: 23186DMG4822SSD-13 Datasheet

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DMN3018SSD-13

Diodes IncorporatedIn Stock: 23174DMN3018SSD-13 Datasheet

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IRF7103TRPBF

Infineon TechnologiesIn Stock: 17412IRF7103TRPBF Datasheet

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SI4816BDY-T1-GE3

Vishay SiliconixIn Stock: 1808SI4816BDY-T1-GE3 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the FDS6984S is determined by strict adherence to the following electrical and mechanical parameters:

Primary Substitution Criteria:

• Drain to Source Voltage (Vdss): Must equal or exceed 30V
• Configuration: Must be 2 N-Channel (Dual) topology
• Package / Case: Must be 8-SOIC (0.154", 3.90mm Width) for mechanical compatibility
• Operating Temperature Range: Must support -55°C to 150°C
• Mounting Type: Must be Surface Mount

Secondary Compatibility Parameters:

• Continuous Drain Current (Id): Substitute must meet or exceed the 5.5A and 8.5A ratings
• On-Resistance (Rds On): Lower or equal values indicate improved performance
• Gate Threshold Voltage (Vgs(th)): Must be compatible with 3V logic level gate operation
• Gate Charge (Qg): Lower values reduce switching losses
• Input Capacitance (Ciss): Lower values improve switching speed

The substitute parts listed below satisfy all primary substitution criteria and maintain electrical compatibility within the specified parameter ranges.

Parameter Comparison

Engineering Selection Recommendations

FDS6986AS (Fairchild Semiconductor)

The FDS6986AS is an active product that maintains electrical equivalence to the FDS6984S across all primary substitution criteria. Both devices share the same 30V Vdss rating, dual N-channel configuration, 8-SOIC package, and operating temperature range. The FDS6986AS provides continuous drain currents of 6.5A and 7.9A, meeting or exceeding the FDS6984S specifications. This part is suitable for direct replacement in applications where the FDS6984S was previously specified.

DMG4822SSD-13 (Diodes Incorporated)

The DMG4822SSD-13 is an active product offering enhanced performance characteristics. It maintains the 30V Vdss rating and 8-SOIC package compatibility. This device provides a continuous drain current of 10A, exceeding the FDS6984S maximum rating. The on-resistance of 20mOhm at 8.5A, 10V is comparable to the FDS6984S. The DMG4822SSD-13 features ROHS3 compliance and is suitable for applications requiring higher current capacity within the same voltage and package constraints.

DMN3018SSD-13 (Diodes Incorporated)

The DMN3018SSD-13 is an active product maintaining 30V Vdss and 8-SOIC package compatibility. It provides a continuous drain current of 6.7A with an on-resistance of 22mOhm at 10A, 10V. The gate threshold voltage is 2.1V at 250µA, which is lower than the FDS6984S specification of 3V. This device features ROHS3 compliance and is suitable for applications where lower gate threshold voltage is acceptable.

SI4816BDY-T1-GE3 (Vishay Siliconix)

The SI4816BDY-T1-GE3 is an active product with 30V Vdss and 8-SOIC package compatibility. It provides continuous drain currents of 5.8A and 8.2A, closely matching the FDS6984S ratings. The on-resistance of 18.5mOhm at 6.8A, 10V is superior to the FDS6984S. This device features ROHS3 compliance and represents a high-performance alternative with improved switching characteristics.

IRF7103TRPBF (Infineon Technologies)

The IRF7103TRPBF is an active product with a 50V Vdss rating, exceeding the FDS6984S specification. It maintains 8-SOIC package compatibility and the required operating temperature range. However, this device provides a continuous drain current of only 3A, which is below the FDS6984S minimum rating of 5.5A. The on-resistance of 130mOhm at 3A, 10V is significantly higher than the FDS6984S. This part is suitable only for applications where lower current requirements and higher voltage margin are acceptable trade-offs.

Frequently Asked Questions (FAQ)

Q: Can the FDS6986AS directly replace the FDS6984S in all applications?

A: The FDS6986AS maintains electrical and mechanical compatibility with the FDS6984S. Both devices share identical Vdss (30V), configuration (2 N-Channel Dual), package (8-SOIC), and operating temperature range (-55°C to 150°C). The FDS6986AS provides continuous drain currents of 6.5A and 7.9A, meeting or exceeding the FDS6984S specifications. Direct replacement is supported for applications within these parameter ranges.

Q: What is the primary difference between the DMG4822SSD-13 and the FDS6984S?

A: The DMG4822SSD-13 provides a higher continuous drain current rating of 10A compared to the FDS6984S maximum of 8.5A. Both devices maintain the same 30V Vdss rating, 8-SOIC package, and operating temperature range. The DMG4822SSD-13 features increased power dissipation capability (1.42W versus 900mW) and lower input capacitance (478.9pF versus 1233pF), resulting in improved switching performance. Selection depends on application current requirements and thermal management considerations.

Q: Is the SI4816BDY-T1-GE3 suitable for applications requiring the exact current ratings of the FDS6984S?

A: The SI4816BDY-T1-GE3 provides continuous drain currents of 5.8A and 8.2A, which closely match the FDS6984S ratings of 5.5A and 8.5A. Both devices maintain 30V Vdss, 8-SOIC package compatibility, and Logic Level Gate operation. The SI4816BDY-T1-GE3 offers superior on-resistance performance (18.5mOhm versus 19mOhm) and lower gate charge (10nC versus 12nC), making it suitable for direct replacement in applications with identical current requirements.

Q: Why is the IRF7103TRPBF listed as a substitute if it has lower current rating?

A: The IRF7103TRPBF is included as a substitute option for applications where voltage margin is prioritized over current capacity. This device provides a 50V Vdss rating compared to the FDS6984S 30V rating, offering enhanced overvoltage protection. The 3A continuous drain current is suitable only for applications with reduced current requirements. Selection of this part requires verification that application current demands do not exceed 3A.

Q: Are all substitute parts available in the same 8-SOIC package?

A: All substitute parts listed are available in the 8-SOIC package with identical physical dimensions (0.154", 3.90mm Width). This ensures mechanical compatibility with existing PCB layouts and assembly processes. Pinout compatibility must be verified against specific application schematics, as configuration differences (Dual versus Half Bridge) may affect circuit operation.

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

A: The FDS6984S carries REACH Unaffected status and EAR99 export classification. Substitute parts DMG4822SSD-13, DMN3018SSD-13, SI4816BDY-T1-GE3, and IRF7103TRPBF are ROHS3 compliant with REACH Unaffected status and EAR99 classification. The FDS6986AS carries REACH Unaffected status and EAR99 classification. All parts maintain Moisture Sensitivity Level 1 (Unlimited). Compliance verification should be performed against specific application and regional requirements.

Q: How does gate charge affect substitute part selection?

A: Gate charge (Qg) determines the energy required to switch the MOSFET and influences switching speed and power loss. The FDS6984S specifies 12nC at 5V. Substitute parts with lower gate charge values (DMG4822SSD-13 at 10.5nC, SI4816BDY-T1-GE3 at 10nC) provide faster switching transitions and reduced switching losses. Substitute parts with higher gate charge values (FDS6986AS at 17nC, IRF7103TRPBF at 30nC) require longer switching times. Selection depends on application switching frequency and thermal constraints.

Q: What is the significance of on-resistance (Rds On) in substitute part selection?

A: On-resistance determines conduction losses and heat generation during normal operation. The FDS6984S specifies 19mOhm at 8.5A, 10V. Lower on-resistance values reduce power dissipation and improve thermal performance. The SI4816BDY-T1-GE3 (18.5mOhm) and DMG4822SSD-13 (20mOhm) offer comparable or superior performance. The FDS6986AS (29mOhm) and IRF7103TRPBF (130mOhm) exhibit higher conduction losses. Selection should consider application current levels and thermal management requirements.