Part A
0451.100MRL
Littelfuse Inc.
- Lifecycle
- Active
- Stock
- 4267 PCS
- Package
- 2-SMD, Square End Block
- Series
- Fuses
Replacement verdict
Compatible functional replacement candidate
The 0451.062MRL is a lower-current-rated fuse of the same series and physical format as the 0451.100MRL, making it a viable functional replacement candidate only where the reduced current rating is acceptable. Both share identical voltage rating, package type, and operating temperature range, but the difference in current rating must be validated against the actual circuit load before substitution.
Current Rating
Validation required
Voltage Rating
High match
Package Type
High match
Operating Temperature
High match
Parts at a glance
Part B
0451.062MRL
Littelfuse Inc.
- Lifecycle
- Active
- Stock
- 4270 PCS
- Package
- 2-SMD, Square End Block
- Series
- Fuses
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 | 0451.062MRL | Why it matters |
|---|---|---|---|
| Current Rating | 100 mA | 62 mA | Determines the maximum continuous current the fuse can carry without opening; a lower-rated fuse will open at lower fault currents. |
| Voltage Rating | 125 V | 125 V | Specifies the maximum voltage the fuse can safely interrupt; must meet or exceed the circuit voltage. |
| Breaking Capacity | 50 A | 50 A | Indicates the maximum fault current the fuse can safely interrupt without damage or hazard. |
| Melting I²t | 0.0025 A²s | 0.001 A²s | Represents the energy required to melt the fuse element; affects opening speed under fault conditions. |
| Nominal Cold Resistance | 3.5 Ohms | 7.5 Ohms | Higher resistance causes greater voltage drop and power loss in normal operation. |
| Voltage Drop at Rated Current | 0.35 V | 0.47 V | Affects the voltage available to the load and overall circuit efficiency. |
| Fuse Type | Slow-Blow (Time-Lag) | Slow-Blow (Time-Lag) | Determines tolerance to inrush currents; slow-blow fuses withstand temporary surges without opening. |
| Package Size | 5 mm x 20 mm | 5 mm x 20 mm | Physical dimensions must match the fuse holder or clip for proper fit and contact. |
| Operating Temperature Range | -55°C to +125°C | -55°C to +125°C | Ensures reliable operation and correct breaking characteristics across the application's temperature range. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 0451.100MRL | 0451.062MRL |
|---|---|---|
| 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) | 100 mA | 62 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 | 0.00138 | 0.00019 |
| 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 0451.062MRL fuses?
The 0451.100MRL and 0451.062MRL are surface-mount, very fast-acting ceramic body fuses from Littelfuse's 451 series. The 0451.100MRL is rated 100 mA and the 0451.062MRL is rated 62 mA, both with a 125 V AC/VDC voltage rating and a 6.1 mm x 2.69 mm footprint.
What is the main difference between the 0451.100MRL and 0451.062MRL?
The primary difference is the current rating: the 0451.100MRL has a 100 mA rating, while the 0451.062MRL has a 62 mA rating. Both share the same 451 series platform, 125 V rating, fast-acting characteristic, and surface-mount ceramic package.
Are the 0451.100MRL and 0451.062MRL interchangeable in a circuit?
No, they are not directly interchangeable because their current ratings differ. Substituting a 100 mA fuse for a 62 mA fuse (or vice versa) changes the overcurrent trip point and can compromise circuit protection. Replacement must follow the original design's specified current rating and the manufacturer's datasheet.
What is the voltage rating of the 0451.100MRL and 0451.062MRL?
Both the 0451.100MRL and 0451.062MRL are rated for 125 V AC and 125 V DC, as specified in the Littelfuse 451 series datasheet.
What is the breaking capacity of the 0451.100MRL and 0451.062MRL?
Both fuses in the Littelfuse 451 series have a breaking capacity of 50 A at 125 V AC and 300 A at 125 V DC, per the manufacturer's datasheet.
What are the physical dimensions and mounting type of these fuses?
The 0451.100MRL and 0451.062MRL are surface-mount fuses in a ceramic body with a footprint of approximately 6.1 mm x 2.69 mm. They are supplied on tape and reel for automated PCB assembly.
What is the operating temperature range for the 0451.100MRL and 0451.062MRL?
Both fuses are rated for operation from -55 °C to +125 °C, according to the Littelfuse 451 series datasheet.
Do the 0451.100MRL and 0451.062MRL carry any agency approvals?
Yes, the Littelfuse 451 series fuses are recognized under UL/CSA and meet relevant industry standards as stated in the manufacturer's datasheet. Designers should confirm the specific approval markings on the current datasheet for the exact part number.