Littelfuse 0278.250V Equivalent & Substitute Parts

Part Overview

The Littelfuse 0278.250V is a 250 mA board mount fuse rated for 125 V AC/DC operation. This component belongs to the MICRO™ 278 series and is designed for through-hole radial mounting in vertical orientation. The part is currently active in production with 999 units in stock. Alternative equivalent parts may be required due to supply constraints, design revisions, or procurement preferences while maintaining identical electrical and mechanical performance.

Substiute Parts

0278.250V

Littelfuse Inc.In Stock: 11040278.250V Datasheet

Current PartRFQ

0272.250H

Littelfuse Inc.In Stock: 9910272.250H Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

The Littelfuse 0272.250H qualifies as a parametric equivalent to the 0278.250V based on the following critical substitution criteria:

All electrical parameters are identical: 250 mA current rating, 125 V AC/DC voltage ratings, fast blow response time, 10 kA breaking capacity, and 0.0064 melting I²t value. The mechanical specifications match exactly: radial can vertical package, 0.235" diameter by 0.287" height, and 1.75 Ohms DC cold resistance. Both components operate across the same temperature range (-55°C to 125°C) and share identical certifications (CSA, QPL, UL). The primary difference is the series designation: 0278.250V belongs to the MICRO™ 278 series while 0272.250H belongs to the MICRO™ 272 series. Both are through-hole board mount fuses with identical form factors and performance characteristics.

Parameter Comparison

Engineering Selection Recommendations

Both the 0278.250V and 0272.250H are active production components from Littelfuse Inc. with full regulatory compliance. Selection between these parts should be based on availability and procurement lead times. Both components carry identical certifications (CSA, QPL, UL) and meet ROHS3 compliance requirements. The 0278.250V currently has 999 units in stock, while the 0272.250H has 975 units available. Either part is suitable for direct substitution in applications requiring a 250 mA, 125 V AC/DC board mount fuse with fast blow response and through-hole radial mounting.

Frequently Asked Questions (FAQ)

Q: Can the 0272.250H replace the 0278.250V in existing designs?

A: Yes. Both parts share identical electrical ratings (250 mA, 125 V AC/DC), response characteristics (fast blow), breaking capacity (10 kA), and physical dimensions (0.235" Dia x 0.287" H). The through-hole radial mounting configuration is identical, allowing direct PCB footprint compatibility.

Q: What is the difference between the MICRO™ 278 and MICRO™ 272 series?

A: The series designation indicates internal design variations within Littelfuse's product line. Both series deliver identical performance parameters for this 250 mA, 125 V specification. The electrical and mechanical characteristics are equivalent for substitution purposes.

Q: Are there any compliance or certification differences?

A: No. Both parts carry identical approvals: CSA, QPL, and UL certifications. Both are ROHS3 compliant and REACH unaffected, meeting the same regulatory requirements.

Q: What is the melting I²t value and why does it matter?

A: The melting I²t of 0.0064 defines the thermal energy required to melt the fuse element. Both parts have identical values, ensuring equivalent protection characteristics and response behavior in overcurrent conditions.

Q: Can these fuses be used in both AC and DC circuits?

A: Yes. Both the 0278.250V and 0272.250H are rated for 125 V AC and 125 V DC operation, making them suitable for either application type.

Q: What is the operating temperature range?

A: Both parts operate across -55°C to 125°C, providing performance stability across industrial and commercial temperature environments.