MQ 750 Equivalent & Substitute Parts Reference

Part Overview

The Bel Fuse Inc. MQ 750 is a 750 mA, 125 V AC/DC board mount axial fuse with fast blow response time, designed for through-hole PCB applications. This part is classified as obsolete, making substitute components necessary for new designs and ongoing production requirements. Equivalent alternatives from active product lines provide functional compatibility while maintaining electrical and mechanical specifications required for direct board-level replacement.

Substiute Parts

MQ 750

Bel Fuse Inc.In Stock: 931MQ 750 Datasheet

Current PartRFQ

0251.750MXL

Littelfuse Inc.In Stock: 7910251.750MXL Datasheet

DirectRFQ

0251.750NRT1L

Littelfuse Inc.In Stock: 1915330251.750NRT1L Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the MQ 750 is determined by strict equivalence across the following electrical and mechanical parameters:

• Current rating: 750 mA (exact match required)
• Voltage ratings: 125 V AC and 125 V DC (exact match required)
• Response time: Fast Blow (exact match required)
• Mounting configuration: Through Hole, Axial package (exact match required)
• Breaking capacity: 50 A AC, 300 A DC (exact match required)
• Operating temperature range: -55°C to 125°C (exact match required)

The Littelfuse Inc. PICO® II 251 series components 0251.750MXL and 0251.750NRT1L meet all electrical and mechanical substitution criteria. Both parts are active products with current manufacturing status, providing long-term availability compared to the obsolete MQ 750.

Parameter Comparison

Engineering Selection Recommendations

Both Littelfuse PICO® II 251 series substitutes (0251.750MXL and 0251.750NRT1L) provide direct functional equivalence to the obsolete MQ 750. Selection between these two alternatives depends on packaging and inventory requirements:

0251.750MXL is supplied in bulk packaging, suitable for high-volume manufacturing environments where component handling and tape-and-reel logistics are managed internally.

0251.750NRT1L is supplied in cut tape (CT) packaging, appropriate for mixed-volume production runs and standard component distribution workflows.

Both parts carry active product status from Littelfuse Inc., ensuring continued manufacturing support and supply chain stability. Regulatory compliance is maintained through CSA, cURus, and TUV certifications, meeting or exceeding the approval requirements of the original MQ 750 component.

Frequently Asked Questions (FAQ)

Q: Can the Littelfuse 0251.750MXL or 0251.750NRT1L be used as direct replacements for the MQ 750 on existing PCBs?

A: Yes. Both parts meet all electrical and mechanical specifications required for direct board-level substitution, including current rating, voltage ratings, response time, mounting configuration, and breaking capacity.

Q: What is the difference between 0251.750MXL and 0251.750NRT1L?

A: The primary difference is packaging format. The 0251.750MXL is supplied in bulk packaging, while the 0251.750NRT1L is supplied in cut tape (CT) packaging. Electrical and mechanical specifications are identical between both parts.

Q: Are there any dimensional differences between the MQ 750 and the Littelfuse substitutes?

A: The MQ 750 has a diameter of 0.125" (3.18 mm), while both Littelfuse substitutes have a diameter of 0.110" (2.80 mm). Both maintain the same axial length of 0.280" (7.10-7.11 mm). The smaller diameter of the Littelfuse parts may require PCB footprint verification for through-hole spacing compatibility.

Q: Do the substitute parts carry the same regulatory certifications?

A: The Littelfuse substitutes carry CSA, cURus, and TUV certifications, which meet or exceed the CE, CSA, and cURus certifications of the original MQ 750.

Q: Why is the MQ 750 listed as obsolete?

A: Obsolete status indicates that Bel Fuse Inc. has discontinued manufacturing this component. Active alternatives from Littelfuse ensure continued availability and supply chain continuity for applications requiring 750 mA, 125 V AC/DC fast blow fuses in axial through-hole configuration.