Littelfuse TE5® 39711000000 Board Mount Fuse - Equivalent & Substitute Parts

Part Overview

The Littelfuse TE5® 39711000000 is a 1 A, 125 V AC board mount radial fuse designed for through-hole PCB applications. This slow-blow fuse provides circuit protection in telecom and industrial equipment with a breaking capacity of 50 A at rated voltage. The part is Active status and widely stocked, with 1053 units available. Alternative equivalent parts are necessary when specific packaging requirements, inventory constraints, or design revisions require substitution while maintaining electrical and mechanical compatibility.

Substiute Parts

39711000000

Littelfuse Inc.In Stock: 110039711000000 Datasheet

Current PartRFQ

38511000000

Littelfuse Inc.In Stock: 650838511000000 Datasheet

DirectRFQ

39611000000

Littelfuse Inc.In Stock: 413939611000000 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the Littelfuse TE5® 39711000000 is determined by strict alignment of the following electrical and mechanical parameters:

Critical Parameters (Must Match Exactly):

• Current Rating: 1 A
• Voltage Rating (AC): 125 V
• Response Time: Slow Blow
• Mounting Type: Through Hole
• Package / Case: Radial, Box
• Physical Dimensions: 0.335" L x 0.157" W x 0.315" H (8.50mm x 4.00mm x 8.00mm)
• Operating Temperature Range: -40°C ~ 85°C
• RoHS Compliance: ROHS3 Compliant

Allowable Variation Parameters:

• Breaking Capacity @ Rated Voltage: 50 A or higher
• Melting I²t: Within acceptable tolerance for slow-blow fuse class
• DC Cold Resistance: Minor variations acceptable within fuse class specifications
• Approval Agencies: cUL, UL, PSE/JET, cURus (all acceptable for board mount fuses)
• Packaging Format: Tape & Box (TB) or Cut Tape (CT) are interchangeable for component selection

The following parts meet all substitution criteria:

39611000000 (Littelfuse TE5® 396 Series) - Direct parametric equivalent with enhanced breaking capacity (100 A)

38511000000 (Littelfuse TE5® 385 Series) - Direct parametric equivalent with alternative series designation

Parameter Comparison

Engineering Selection Recommendations

All three parts are Active status products from Littelfuse Inc. and maintain full ROHS3 compliance and REACH unaffected status. Selection between these equivalents should be based on the following factors:

39711000000 (Primary Part): Use when original part number specification is required or when 50 A breaking capacity is sufficient for the application. Moderate inventory availability.

39611000000 (TE5® 396 Series): Use as substitute when enhanced breaking capacity (100 A) is beneficial for circuit protection margin. Includes PSE/JET approval in addition to cUL and UL certifications, expanding geographic compliance scope. Higher inventory availability (4100 units).

38511000000 (TE5® 385 Series): Use as substitute when Cut Tape packaging is preferred over Tape & Box format. Highest inventory availability (6417 units). Approved under cURus certification. Melting I²t of 4.5 represents slightly slower response within slow-blow classification.

All three parts share identical electrical ratings (1 A, 125 V AC), response time (Slow Blow), mounting configuration (Through Hole), and physical dimensions (8.50mm x 4.00mm x 8.00mm). PCB layout and footprint compatibility is guaranteed across all three substitutes.

Frequently Asked Questions (FAQ)

Q: Can 39611000000 replace 39711000000 in my circuit?

A: Yes. Both parts are 1 A, 125 V AC slow-blow board mount fuses with identical physical dimensions and through-hole mounting. The 39611000000 offers higher breaking capacity (100 A vs. 50 A), which provides additional protection margin without affecting normal circuit operation.

Q: What is the difference between Tape & Box (TB) and Cut Tape (CT) packaging?

A: Tape & Box and Cut Tape are packaging formats for component delivery and storage. Both formats contain the same electrical component. TB includes a protective box; CT is supplied on tape only. Selection depends on assembly line requirements and storage preferences. Electrical performance is identical.

Q: Are all three parts suitable for telecom applications?

A: Yes. The 38511000000 explicitly lists telecom applications. The 39711000000 and 39611000000 share identical electrical specifications and are suitable for the same applications. All three are approved for industrial and telecom circuit protection.

Q: What does "Slow Blow" mean for these fuses?

A: Slow Blow (also called time-delay) fuses tolerate temporary current surges without opening. They open only when sustained overcurrent is detected. This characteristic is identical across all three substitute parts and is appropriate for circuits with inrush current during startup.

Q: Can I use these fuses in DC circuits?

A: These fuses are rated for 125 V AC. The 39711000000 and 39611000000 specifications include "AC DC" designation, indicating DC compatibility at the same voltage rating. The 38511000000 is specified for 125 VAC. Verify DC application requirements with circuit design specifications.

Q: What is the significance of the Melting I²t value?

A: Melting I²t indicates the thermal energy required to melt the fuse element. Lower values (39611000000 at 3.25) indicate faster response to overcurrent; higher values (38511000000 at 4.5) indicate slightly delayed response. All three are within slow-blow fuse class specifications and are interchangeable for standard circuit protection applications.

Q: Which part should I choose if inventory is critical?

A: The 38511000000 has the highest inventory (6417 units), followed by 39611000000 (4100 units), and 39711000000 (1053 units). If immediate availability is required, 38511000000 is the optimal choice while maintaining full electrical and mechanical compatibility.