MQ 375 Equivalent & Substitute Parts

Part Overview

The MQ 375 is a 375 mA board mount axial fuse rated for 125 V AC/DC operation, manufactured by Bel Fuse Inc. This component is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system support and component procurement. The MQ 375 serves as a protective device in through-hole applications requiring fast-blow response characteristics and compact axial packaging.

Substiute Parts

MQ 375

Bel Fuse Inc.In Stock: 871MQ 375 Datasheet

Current PartRFQ

0251.375MXL

Littelfuse Inc.In Stock: 18530251.375MXL Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the MQ 375 is determined by strict equivalence across the following electrical and mechanical parameters:

• Current Rating: 375 mA (exact match required)
• Voltage Rating: 125 V AC and 125 V DC (both must be met)
• Response Time: Fast Blow (protection characteristic must match)
• Mounting Type: Through Hole (board assembly compatibility)
• Package / Case: Axial (physical form factor and PCB footprint)
• Breaking Capacity: 50A AC, 300A DC (fault protection capability)
• Operating Temperature: -55°C ~ 125°C (environmental compatibility)

The 0251.375MXL from Littelfuse Inc. meets all these criteria and qualifies as a direct functional equivalent.

Parameter Comparison

Engineering Selection Recommendations

The 0251.375MXL (Littelfuse PICO® II 251 series) is the qualified substitute for the obsolete MQ 375. Selection is based on:

• Electrical equivalence across all rated parameters (current, voltage AC/DC, breaking capacity)
• Identical response time classification (Fast Blow)
• Matching mechanical form factor (Through Hole Axial)
• Active product status ensuring ongoing availability and supply chain continuity
• Regulatory compliance through CSA and cURus certifications, with cURus approval common to both parts
• Operating temperature range compatibility (-55°C ~ 125°C)

The 0251.375MXL is available in bulk packaging with 1776 pieces in stock, supporting both prototype and production-level procurement requirements.

Frequently Asked Questions (FAQ)

Q: Can the 0251.375MXL be used as a direct replacement for the MQ 375 without circuit modification?

A: Yes. The 0251.375MXL meets all electrical and mechanical specifications of the MQ 375, including current rating, voltage ratings, response time, and breaking capacity. Through-hole axial mounting is identical, allowing direct PCB substitution.

Q: What is the significance of the DC Cold Resistance difference (0.41 Ω vs 0.395 Ω)?

A: The DC Cold Resistance values are within acceptable tolerance for fuse substitution. Both values are sufficiently low to prevent unwanted voltage drop during normal circuit operation and do not affect the protective function.

Q: Why is the MQ 375 listed as obsolete?

A: Obsolete status indicates the MQ 375 is no longer manufactured by Bel Fuse Inc. The 0251.375MXL from Littelfuse provides functional continuity for systems requiring this fuse specification.

Q: Are there differences in approval certifications between the two parts?

A: Both parts carry CSA and cURus certifications. The MQ 375 additionally lists CE approval. For applications requiring CE compliance, verification with the 0251.375MXL documentation is recommended based on specific regional requirements.

Q: Does the PICO® II 251 series designation affect compatibility?

A: No. The series designation identifies the product line within Littelfuse's portfolio. Compatibility is determined by the electrical and mechanical parameters, which are equivalent between the MQ 375 and 0251.375MXL.