Littelfuse 0664.800HXLL Equivalent & Substitute Parts

Part Overview

The Littelfuse 0664.800HXLL is an 800 mA, 250 V AC/DC board mount fuse with radial, can-style vertical packaging. This component belongs to the LT-5™ 664 series and features slow-blow response characteristics suitable for circuit protection applications requiring controlled thermal response. The part is classified as obsolete, making identification of active equivalent components essential for ongoing design support and procurement continuity.

Substiute Parts

0664.800HXLL

Littelfuse Inc.In Stock: 10800664.800HXLL Datasheet

Current PartRFQ

37208000001

Littelfuse Inc.In Stock: 309737208000001 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the obsolete 0664.800HXLL is based on matching the following critical electrical and mechanical parameters:

• Current Rating: 800 mA (exact match required)
• Voltage Rating: 250 V AC (exact match required)
• Response Time: Slow Blow (exact match required)
• Mounting Type: Through Hole (exact match required)
• Package Style: Radial, Can, Vertical (exact match required)
• Operating Temperature Range: -40°C to 85°C (minimum requirement)
• RoHS Compliance: ROHS3 Compliant (regulatory requirement)

The substitute part 37208000001 from Littelfuse Inc. satisfies all these criteria while offering active product status and improved availability.

Parameter Comparison

Engineering Selection Recommendations

The 37208000001 is the manufacturer-recommended substitute for the obsolete 0664.800HXLL. Both components share identical electrical ratings (800 mA, 250 V AC, slow-blow response) and mounting characteristics (through-hole, radial can-style vertical package). The substitute maintains full RoHS3 compliance and operates within the same temperature range.

The substitute part offers active product status with significantly higher inventory availability (3080 pcs vs. 995 pcs), ensuring long-term procurement reliability. Both components carry equivalent regulatory approvals from SEMKO and VDE. The dimensional difference of 0.018" in height (8.45mm vs. 8.00mm) is within typical PCB layout tolerances for through-hole radial components.

The lower DC cold resistance of the substitute (0.1 Ohms vs. 0.168 Ohms) represents an improvement in electrical performance characteristics without affecting the functional current and voltage ratings.

Frequently Asked Questions (FAQ)

Q: Can the 37208000001 be used as a direct replacement for the 0664.800HXLL?

A: Yes. Both components share identical current ratings (800 mA), voltage ratings (250 V AC), response time (slow blow), mounting type (through hole), and package style (radial, can, vertical). The substitute is the manufacturer-recommended equivalent.

Q: What is the significance of the height difference between these parts?

A: The main part measures 0.333" H (8.45mm) while the substitute measures 0.315" H (8.00mm). This 0.018" difference is typical for through-hole radial fuse components and does not affect PCB compatibility or circuit performance.

Q: Are the regulatory approvals equivalent?

A: Both parts carry SEMKO and VDE approvals. The main part includes CSA and KTL approvals, while the substitute includes CCC and cURus approvals. These represent equivalent regulatory compliance for their respective markets.

Q: Why is the substitute part recommended despite the obsolete status of the main part?

A: The substitute is an active product from the same manufacturer with identical electrical specifications and superior availability. It provides design continuity and ensures long-term component sourcing for applications currently using the 0664.800HXLL.

Q: Does the lower DC cold resistance of the substitute affect circuit operation?

A: No. The DC cold resistance difference (0.1 Ohms vs. 0.168 Ohms) does not affect the fuse's primary function. Both values are within acceptable ranges for 800 mA fuses and represent normal variation between product series.