FDR8305N Equivalent & Substitute Parts

Part Overview

The FDR8305N is a dual N-channel MOSFET array manufactured by onsemi, designed for surface mount applications in the PowerTrench® series. This device features a 20V drain-to-source voltage rating with 4.5A continuous drain current capability and logic level gate operation. The FDR8305N is classified as obsolete, necessitating identification of functionally equivalent alternatives for new designs and ongoing production requirements. Substitute parts must maintain electrical compatibility across critical parameters including voltage rating, current capacity, and gate characteristics while accommodating package and availability constraints.

Substiute Parts

FDR8305N

onsemiIn Stock: 1229FDR8305N Datasheet

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FDS6890A

onsemiIn Stock: 20291FDS6890A Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the FDR8305N is determined by strict adherence to the following electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Drain-to-source voltage (Vdss) must equal or exceed 20V
• Continuous drain current (Id) must equal or exceed 4.5A at 25°C
• Gate threshold voltage (Vgs(th)) must be compatible with logic level gate operation (≤1.5V @ 250µA)
• On-state resistance (Rds On) should not exceed the specified maximum to maintain thermal performance
• Operating temperature range must encompass -55°C to 150°C

Mechanical Compatibility Criteria:

• Configuration must be dual N-channel (2 N-Channel)
• Mounting type must be surface mount
• Package footprint must be compatible with PCB layout requirements

Functional Criteria:

• Technology must be MOSFET (Metal Oxide)
• Series designation should be PowerTrench® or equivalent performance class
• FET feature must support logic level gate operation

The FDS6890A meets these substitution criteria with enhanced electrical performance characteristics while maintaining functional equivalence.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: FDS6890A

The FDS6890A is the recommended substitute for the obsolete FDR8305N based on the following engineering criteria:

Electrical Performance: The FDS6890A maintains identical voltage rating (20V Vdss) and gate threshold voltage (1.5V @ 250µA), ensuring direct functional compatibility. The substitute provides enhanced current capacity (7.5A versus 4.5A) and improved on-state resistance (18mOhm versus 22mOhm), resulting in superior thermal performance and reduced power dissipation in equivalent operating conditions.

Compliance and Certification: Both devices share identical REACH status (REACH Unaffected), ECCN classification (EAR99), and HTSUS tariff code (8541.21.0095). The FDS6890A carries RoHS3 compliance certification, providing additional regulatory assurance for new designs.

Product Status and Availability: The FDS6890A is classified as active product with substantial inventory availability (20,200 pieces), ensuring long-term supply continuity. The FDR8305N is obsolete, making the FDS6890A the appropriate selection for ongoing production and new design implementations.

Package Consideration: The FDS6890A uses an 8-SOIC package (0.154", 3.90mm width) compared to the FDR8305N SuperSOT™-8 package (0.130", 3.30mm width). PCB layout modification is required to accommodate the different footprint dimensions.

Thermal and Switching Characteristics: The FDS6890A exhibits higher gate charge (32nC versus 23nC) and input capacitance (2130pF versus 1600pF), which may result in slightly increased switching losses in high-frequency applications. These differences are within acceptable engineering tolerances for most applications operating within the specified electrical parameters.

Frequently Asked Questions (FAQ)

Q: Can the FDS6890A directly replace the FDR8305N without circuit modification?

A: The FDS6890A provides electrical substitution with enhanced performance characteristics. However, the different package footprint (8-SOIC versus SuperSOT™-8) requires PCB layout redesign. No circuit topology changes are necessary if the PCB layout is updated to accommodate the new package dimensions.

Q: What are the key electrical differences between these devices?

A: Both devices maintain identical voltage rating (20V) and gate threshold voltage (1.5V @ 250µA). The FDS6890A provides higher continuous drain current (7.5A versus 4.5A), lower on-state resistance (18mOhm versus 22mOhm), and higher power dissipation rating (900mW versus 800mW). These represent performance enhancements rather than incompatibilities.

Q: Are there any thermal performance implications when using the FDS6890A?

A: The FDS6890A exhibits lower on-state resistance, which reduces resistive heating at equivalent current levels. The higher power dissipation rating (900mW) provides additional thermal margin. Higher gate charge and input capacitance may increase switching losses in high-frequency applications, but this effect is typically negligible in standard switching applications.

Q: What is the impact of the different package types on PCB design?

A: The FDS6890A 8-SOIC package (0.154", 3.90mm width) is wider than the FDR8305N SuperSOT™-8 package (0.130", 3.30mm width). PCB layout must be updated to accommodate the new footprint. Pin-to-pin spacing and overall package dimensions differ, requiring schematic symbol and footprint library updates in design tools.

Q: Is the FDS6890A suitable for applications requiring the original FDR8305N specifications?

A: Yes. The FDS6890A meets or exceeds all critical electrical specifications of the FDR8305N. The enhanced current capacity and reduced on-state resistance make it suitable for applications originally designed for the FDR8305N. Package footprint compatibility must be verified during PCB layout design.

Q: What compliance certifications apply to the FDS6890A?

A: The FDS6890A carries RoHS3 compliance certification and maintains REACH Unaffected status. Both devices share identical ECCN (EAR99) and HTSUS (8541.21.0095) classifications, ensuring regulatory consistency for export and procurement purposes.

Q: Are there any gate drive considerations when switching from FDR8305N to FDS6890A?

A: Both devices feature logic level gate operation with identical threshold voltage (1.5V @ 250µA). The FDS6890A exhibits higher gate charge (32nC versus 23nC), requiring slightly more gate drive energy. Standard logic level gate drivers compatible with the FDR8305N remain compatible with the FDS6890A.

Q: What is the moisture sensitivity level for the FDS6890A?

A: The FDS6890A carries MSL rating 1 (Unlimited), identical to the FDR8305N. This indicates minimal moisture sensitivity and no special storage or handling requirements beyond standard component handling practices.