FDC6401N Equivalent & Substitute Parts

Part Overview

The FDC6401N is a dual N-channel MOSFET array manufactured by onsemi, designed for surface mount applications in the PowerTrench® series. This device integrates two N-channel MOSFETs in a compact SuperSOT™-6 package, rated for 20V drain-to-source voltage and 3A continuous drain current. The part is currently in active production status with extensive inventory availability.

Substitute parts become necessary when the primary device reaches end-of-life status, when specific package requirements differ from application constraints, or when alternative thermal or electrical performance characteristics are required for system optimization.

Substiute Parts

FDC6401N

onsemiIn Stock: 35444FDC6401N Datasheet

Current PartRFQ

NTHD4508NT1G

onsemiIn Stock: 17082NTHD4508NT1G Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the FDC6401N is determined by strict alignment of the following electrical and mechanical parameters:

Critical Matching Parameters:

• Drain to Source Voltage (Vdss): 20V
• Continuous Drain Current (Id): 3A minimum
• Configuration: Dual N-Channel
• Mounting Type: Surface Mount
• Operating Temperature Range: -55°C to 150°C minimum

Acceptable Variation Parameters:

• Rds On (Max): Substitute values must not exceed the application's thermal budget; lower values are acceptable
• Gate Charge (Qg): Lower values improve switching performance; higher values are acceptable within thermal constraints
• Input Capacitance (Ciss): Variation acceptable based on circuit switching frequency requirements
• Power Dissipation (Max): Higher ratings provide additional thermal margin
• Package form factor: Different surface mount packages acceptable if PCB layout accommodates physical dimensions

The NTHD4508NT1G meets all critical matching parameters and is therefore classified as a functional equivalent to the FDC6401N.

Parameter Comparison

Engineering Selection Recommendations

FDC6401N (Primary Selection)

The FDC6401N is the preferred component for new designs and ongoing production. This device maintains active product status with onsemi, ensuring long-term availability and supply chain stability. The part carries full RoHS3 compliance and REACH unaffected status, meeting current environmental and regulatory requirements. The SuperSOT™-6 package provides a compact form factor optimized for space-constrained applications. Inventory levels of 35,400 units support immediate procurement without lead-time constraints.

NTHD4508NT1G (Substitute Selection)

The NTHD4508NT1G serves as a functional equivalent for applications where the FDC6401N becomes unavailable. This substitute maintains identical voltage and current ratings (20V, 3A) and dual N-channel configuration. The NTHD4508NT1G offers superior thermal performance with a maximum power rating of 1.13W compared to the FDC6401N's 700mW, providing additional thermal margin in power-dissipation-limited applications. The device exhibits lower gate charge (4nC versus 4.6nC) and reduced input capacitance (180pF versus 324pF), resulting in improved switching characteristics.

Critical Consideration: The NTHD4508NT1G carries obsolete product status. While current inventory of 17,072 units is available, this part is no longer in active production. Selection of this substitute is appropriate only when the FDC6401N is unavailable and the application timeline permits use of legacy inventory. The different package form factor (8-SMD, Flat Lead versus SOT-23-6 Thin) requires PCB layout modification and requalification.

Both devices maintain identical operating temperature ranges (-55°C to 150°C), RoHS3 compliance, and MSL 1 moisture sensitivity ratings, ensuring compatibility with standard manufacturing and storage protocols.

Frequently Asked Questions (FAQ)

Q: Can the NTHD4508NT1G directly replace the FDC6401N without PCB modification?

A: No. The NTHD4508NT1G uses an 8-SMD, Flat Lead package, while the FDC6401N uses SOT-23-6 Thin (TSOT-23-6) package. These packages have different physical dimensions and pin configurations. PCB layout redesign and component footprint modification are required. Pin-to-pin functional equivalence does not eliminate the need for physical package compatibility verification.

Q: What are the key electrical differences between these two parts?

A: Both devices share identical voltage (20V) and current (3A) ratings. The NTHD4508NT1G provides superior thermal performance (1.13W versus 700mW maximum power) and lower switching losses (4nC gate charge versus 4.6nC, 180pF input capacitance versus 324pF). The NTHD4508NT1G exhibits a lower gate threshold voltage (1.2V versus 1.5V), which may affect gate drive circuit design in applications with marginal gate voltage margins.

Q: Why is the NTHD4508NT1G listed as obsolete?

A: Obsolete status indicates that onsemi has discontinued active production of this part. Existing inventory remains available for purchase, but no new manufacturing runs are scheduled. This status does not affect the electrical or mechanical performance of units currently in stock; it reflects manufacturing lifecycle decisions by the supplier.

Q: Are both parts RoHS3 compliant?

A: Yes. Both the FDC6401N and NTHD4508NT1G carry full RoHS3 compliance certification and REACH unaffected status, meeting current environmental regulations for electronic components in regulated markets.

Q: What is the moisture sensitivity level for these devices?

A: Both devices carry MSL 1 (Unlimited) rating, indicating no moisture sensitivity restrictions. Standard dry storage and handling procedures are not required, and these parts do not require baking before reflow soldering.

Q: Can I use the NTHD4508NT1G in a design originally qualified with the FDC6401N?

A: Electrical substitution is valid based on matching voltage, current, and temperature specifications. However, the different package form factor requires PCB layout changes and thermal analysis verification. The improved thermal performance of the NTHD4508NT1G may alter thermal behavior in the application. Full design requalification including thermal testing is necessary before production implementation.

Q: Which part should I specify for a new design?

A: Specify the FDC6401N for new designs. This device maintains active production status, ensuring long-term supply availability and design stability. The NTHD4508NT1G should be reserved for legacy system maintenance or situations where the FDC6401N becomes unavailable during the product lifecycle.