Part A
0451001.MRL
Littelfuse Inc.
- Lifecycle
- Active
- Stock
- 7334 Stückzahl
- Package
- 2-SMD
- Series
- Sicherungen
Replacement verdict
Compatible functional replacement candidate
The 0451001.MRL and 0451010.MRL are both fast-acting surface-mount fuses from the same Littelfuse NANO2 series, sharing identical package, voltage rating, and interrupting capacity. The primary distinction is the current rating, making the 0451010.MRL a viable higher-current alternative only where the circuit's continuous current and fault protection requirements are compatible with the increased amperage rating.
Current Rating
Not compatible
Package Type
High match
Voltage Rating
High match
Interrupting Rating
High match
Parts at a glance
Part B
0451010.MRL
Littelfuse Inc.
- Lifecycle
- Active
- Stock
- 7413 Stückzahl
- Package
- SMD-2
- Series
- Sicherungen
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 0451001.MRL | 0451010.MRL | Why it matters |
|---|---|---|---|
| Current Rating | 1 A | 10 A | Determines the maximum continuous current the fuse can carry without opening; a direct functional difference affecting circuit protection level. |
| Voltage Rating | 125 VAC / 125 VDC | 125 VAC / 125 VDC | Defines the maximum voltage the fuse can safely interrupt; must meet or exceed the circuit voltage for safe operation. |
| Interrupting Rating | 50 A at 125 VAC / 50 A at 125 VDC | 50 A at 125 VAC / 50 A at 125 VDC | Indicates the maximum fault current the fuse can safely break without damage or hazard. |
| Melting I²t | 0.42 A²s | 26.5 A²s | Represents the energy required to open the fuse; affects response time and coordination with downstream components. |
| Nominal Cold Resistance | 0.145 Ohms | 0.0075 Ohms | Lower resistance reduces voltage drop and power loss; impacts circuit efficiency and thermal behavior. |
| Voltage Drop at Rated Current | 0.145 V | 0.075 V | Affects the voltage available to the load and power dissipation within the fuse during normal operation. |
| Fuse Type | Fast-Acting (Nano²) | Fast-Acting (Nano²) | Determines the time-current characteristic; fast-acting fuses respond quickly to overcurrents, protecting sensitive components. |
| Package / Size | Nano² SMF (6.1 mm x 2.69 mm) | Nano² SMF (6.1 mm x 2.69 mm) | Physical footprint and mounting type must match the PCB layout for direct substitutability. |
| Operating Temperature Range | -55°C to +125°C | -55°C to +125°C | Ensures reliable operation across the application's environmental conditions; derating may apply at extremes. |
| Approvals / Standards | UL Recognized, CSA Certified, PSE | UL Recognized, CSA Certified, PSE | Compliance with safety and regulatory standards is required for end-product certification and market acceptance. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 0451001.MRL | 0451010.MRL |
|---|---|---|
| Series | NANO²® 451 | NANO²® 451 |
| Part Status | Active | Active |
| Mounting Type | Surface Mount | Surface Mount |
| Fuse Type | Board Mount (Cartridge Style Excluded) | Board Mount (Cartridge Style Excluded) |
| Current Rating (Amps) | 1 A | 10 A |
| Voltage Rating - AC | 125 V | 125 V |
| Voltage Rating - DC | 125 V | 125 V |
| Response Time | Fast Blow | Fast Blow |
| Breaking Capacity @ Rated Voltage | 50A | 35A AC, 50A DC |
| Melting I²t | 0.459 | 26.46 |
| Approval Agency | CSA, PSE, UL | CSA, PSE, UL |
| Operating Temperature | -55°C ~ 125°C | -55°C ~ 125°C |
Frequently asked questions
What are the 0451001.MRL and 0451010.MRL fuses?
The 0451001.MRL and 0451010.MRL are surface-mount fuses from Littelfuse's 451 series, a family of very fast-acting, ceramic body fuses designed for overcurrent protection in compact electronic circuits.
What is the current rating difference between the 0451001.MRL and 0451010.MRL?
The 0451001.MRL is rated at 1 A, while the 0451010.MRL is rated at 10 A. This is the primary functional difference between the two part numbers.
Do the 0451001.MRL and 0451010.MRL share the same voltage rating?
Yes. Both the 0451001.MRL and 0451010.MRL are rated for 125 V AC and 125 V DC, allowing them to be used in circuits up to that voltage level.
Are the 0451001.MRL and 0451010.MRL interchangeable in a design?
No. Although they share the same package, voltage rating, and series characteristics, their current ratings differ by a factor of ten. Substitution must only be considered after verifying the circuit's normal operating current, fault current profile, and the fuse's melting I²t against the manufacturer datasheet.
What package and mounting type do the 0451001.MRL and 0451010.MRL use?
Both fuses are supplied in a surface-mount, ceramic body package with a footprint commonly associated with the 451 series. They are intended for automated PCB assembly and reflow soldering processes.
What is the breaking capacity of the 0451001.MRL and 0451010.MRL?
Both the 0451001.MRL and 0451010.MRL have a breaking capacity of 50 A at 125 V AC and 50 A at 125 V DC, meaning they can safely interrupt fault currents up to that level without sustaining damage or failing to clear the circuit.
Are the 0451001.MRL and 0451010.MRL RoHS compliant?
Yes. Both the 0451001.MRL and 0451010.MRL are RoHS compliant and lead-free, in accordance with the Littelfuse 451 series environmental specifications.
What are typical applications for the 0451001.MRL and 0451010.MRL?
These fuses are typically used for overcurrent protection in battery packs, power supplies, consumer electronics, and other compact circuits where a fast-acting, surface-mount fuse with a 125 V rating is required. The 0451001.MRL suits lower-current rails, while the 0451010.MRL suits higher-current rails.