Part A
0451.200MRL
리틀퓨즈(주)
- Lifecycle
- Active
- Stock
- 2434 PCS
- Package
- 2-SMD, Square End Block
- Series
- 퓨즈
Replacement verdict
Compatible functional replacement candidate
The 0451.100MRL and 0451.200MRL are both fast-acting subminiature axial lead fuses from the Littelfuse 451 series, sharing identical physical dimensions, voltage ratings, and interrupting capacity. The only meaningful difference is the current rating, making the 0451.200MRL a viable higher-current alternative to the 0451.100MRL provided the application's overcurrent protection threshold can accommodate the increased rating.
Current Rating
Validation required
Voltage Rating
High match
Package Type
High match
Breaking Capacity
High match
Parts at a glance
Part B
0451.100MRL
리틀퓨즈(주)
- Lifecycle
- Active
- Stock
- 4267 PCS
- Package
- 2-SMD, Square End Block
- Series
- 퓨즈
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 0451.100MRL | 0451.200MRL | Why it matters |
|---|---|---|---|
| Current Rating | 100 mA | 200 mA | Determines the maximum continuous current the fuse can carry without opening; a higher rating allows more current before interruption. |
| Voltage Rating | 125 V | 125 V | Specifies the maximum voltage the fuse can safely interrupt; must meet or exceed the circuit voltage. |
| Interrupting Rating | 50 A | 50 A | Indicates the maximum fault current the fuse can safely break without damage or hazard. |
| Melting I²t | 0.0025 A²s | 0.012 A²s | Represents the energy required to melt the fuse element; affects opening speed under overcurrent conditions. |
| Nominal Cold Resistance | 2.5 Ohms | 0.85 Ohms | Lower resistance reduces voltage drop and power loss in normal operation. |
| Voltage Drop at Rated Current | 0.25 V | 0.17 V | Affects circuit efficiency and heat generation; lower drop is preferable for sensitive loads. |
| Operating Temperature Range | -55°C to +125°C | -55°C to +125°C | Defines the environmental conditions under which the fuse maintains reliable performance. |
| Package / Size | SMD, 1206 | SMD, 1206 | Physical footprint must match the PCB layout for direct substitution. |
| Approvals / Standards | UL, CSA, VDE | UL, CSA, VDE | Certifications ensure compliance with safety and regulatory requirements for the target market. |
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Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 0451.200MRL | 0451.100MRL |
|---|---|---|
| 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) | 200 mA | 100 mA |
| 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 | 50A |
| Melting I²t | 0.0089 | 0.00138 |
| Approval Agency | CSA, UL | CSA, UL |
| Operating Temperature | -55°C ~ 125°C | -55°C ~ 125°C |
Frequently asked questions
What are the 0451.100MRL and 0451.200MRL fuses?
The 0451.100MRL and 0451.200MRL are surface-mount, very fast-acting ceramic body fuses from Littelfuse's 451 series. The 0451.100MRL is rated 100 mA and the 0451.200MRL is rated 200 mA, both with a 125 V AC/DC voltage rating and a 2410 (6125 metric) footprint.
What is the main difference between the 0451.100MRL and 0451.200MRL?
The primary difference is the current rating: the 0451.100MRL has a 100 mA rating, while the 0451.200MRL has a 200 mA rating. Both share the same 451 series platform, 125 V rating, very fast-acting characteristic, and 2410 surface-mount package.
Are the 0451.100MRL and 0451.200MRL interchangeable?
No. Although they share the same package and voltage rating, their current ratings differ by a factor of two. Substitution must be evaluated against the circuit's normal operating current, inrush profile, and required breaking capacity using the Littelfuse 451 series datasheet.
What is the voltage rating of the 0451.100MRL and 0451.200MRL?
Both the 0451.100MRL and 0451.200MRL are rated for 125 V AC and 125 V DC, as specified in the Littelfuse 451 series datasheet.
What is the interrupting rating of these fuses?
The Littelfuse 451 series datasheet specifies a breaking capacity of 50 A at 125 V AC and 300 A at 125 V DC for these very fast-acting ceramic fuses.
What package and mounting type do the 0451.100MRL and 0451.200MRL use?
Both fuses use a 2410 (6125 metric) surface-mount ceramic package with a rectangular body and end terminations, suitable for reflow soldering on standard PCB land patterns.
What are typical applications for the 0451.100MRL and 0451.200MRL?
These very fast-acting fuses are typically used for overcurrent protection in space-constrained electronics such as battery packs, power supplies, consumer electronics, and industrial control boards where fast response to fault currents is required.
Do the 0451.100MRL and 0451.200MRL carry the same agency approvals?
Both are part of the Littelfuse 451 series and share the same series-level agency recognitions, including UL and CSA listings as stated in the Littelfuse 451 series datasheet. Always confirm the specific approval markings on the current datasheet revision.