FCD121400TP Equivalent & Substitute Parts

Part Overview

The FCD121400TP is a 4 A surface mount board mount fuse rated for 32 V DC operation in a 1206 (3216 Metric) package. Manufactured by Littelfuse Inc., this component is classified as obsolete product status. Due to its obsolete designation, equivalent substitute parts with active product status are available to ensure continued design support and supply chain reliability.

Substiute Parts

FCD121400TP

Littelfuse Inc.In Stock: 853FCD121400TP Datasheet

Current PartRFQ

0437004.WR

Littelfuse Inc.In Stock: 152460437004.WR Datasheet

DirectRFQ

0466004.NR

Littelfuse Inc.In Stock: 158710466004.NR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the FCD121400TP is determined by the following core parameters:

• Current Rating: 4 A (exact match required)
• Package / Case: 1206 (3216 Metric) (exact match required)
• Mounting Type: Surface Mount (exact match required)
• Fuse Type: Board Mount (Cartridge Style Excluded) (exact match required)
• Response Time: Fast Blow (exact match required)
• Breaking Capacity @ Rated Voltage: 50 A (exact match required)
• RoHS Status: ROHS3 Compliant (exact match required)

Two substitute parts meet these criteria:

1. 0437004.WR - Direct substitute with enhanced DC voltage rating (35 V DC vs. 32 V DC)
2. 0466004.NR - Manufacturer recommended substitute with matched DC voltage rating (32 V DC)

Parameter Comparison

Engineering Selection Recommendations

0437004.WR is a direct functional substitute with active product status. This part provides a higher DC voltage rating (35 V vs. 32 V), offering additional design margin in DC applications. The extended operating temperature range (-55°C ~ 150°C) supports broader environmental conditions. Approval certifications include CSA and UR. This substitute is suitable for applications where the higher voltage rating does not conflict with circuit design constraints.

0466004.NR is the manufacturer recommended substitute with active product status. This part maintains the original 32 V DC voltage rating, providing exact electrical compatibility with the FCD121400TP. The SlimLine™ 466 series designation indicates a compact form factor. Approval certifications include CSA and UL. This substitute is recommended for direct replacement in existing designs requiring no circuit modification.

Both substitutes carry ROHS3 compliance, MSL Level 1 rating, and identical current and breaking capacity specifications. Selection between the two substitutes depends on voltage margin requirements and operating temperature constraints specific to the application.

Frequently Asked Questions (FAQ)

Q: Can 0437004.WR be used in place of FCD121400TP in a 32 V DC circuit?

A: Yes. The 0437004.WR has a 35 V DC rating, which exceeds the 32 V DC requirement of the original part. This provides additional voltage margin and is electrically compatible.

Q: What is the difference between 0437004.WR and 0466004.NR?

A: Both are 4 A fast blow fuses in 1206 packages with identical current and breaking capacity ratings. Key differences are: 0437004.WR has 35 V DC rating and -55°C ~ 150°C operating range; 0466004.NR has 32 V DC rating and -55°C ~ 90°C operating range. 0466004.NR is the manufacturer recommended direct replacement.

Q: Are the physical dimensions identical between all three parts?

A: Dimensions are similar but not identical. FCD121400TP: 3.20mm × 1.60mm × 0.65mm; 0437004.WR: 3.20mm × 1.63mm × 0.82mm; 0466004.NR: 3.18mm × 1.52mm × 0.58mm. All fit the 1206 package specification and are suitable for standard PCB layouts.

Q: Which substitute should I select for new designs?

A: Selection is based on application requirements. For exact voltage matching and manufacturer recommendation, use 0466004.NR. For applications requiring higher voltage margin and extended temperature range, use 0437004.WR.

Q: Are both substitutes RoHS compliant?

A: Yes. Both 0437004.WR and 0466004.NR are ROHS3 compliant with MSL Level 1 rating (unlimited moisture sensitivity).

Q: What are the approval certifications for each substitute?

A: 0437004.WR carries CSA and UR certifications. 0466004.NR carries CSA and UL certifications. Both meet industry safety standards for board mount fuses.