Littelfuse 04371.75WRP Surface Mount Fuse - Equivalent & Substitute Parts

Part Overview

The Littelfuse 04371.75WRP is an active, surface mount board fuse rated at 1.75A with 63V AC/DC voltage capability. This fast-blow fuse is designed for circuit protection in compact 1206 (3216 Metric) package configurations. Finding equivalent and substitute parts is necessary to ensure design flexibility, manage supply chain continuity, and maintain component availability across manufacturing cycles.

Substiute Parts

04371.75WRP

Littelfuse Inc.In Stock: 112604371.75WRP Datasheet

Current PartRFQ

04371.75WR

Littelfuse Inc.In Stock: 369904371.75WR Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

The Littelfuse 04371.75WR qualifies as a parametric equivalent to the 04371.75WRP based on the following critical substitution criteria:

• Current Rating: Identical at 1.75 A
• Voltage Rating: Identical at 63V AC and 63V DC
• Response Time: Identical fast-blow characteristic
• Package / Case: Identical 1206 (3216 Metric) surface mount configuration
• Mounting Type: Identical surface mount
• Breaking Capacity: Identical 50A @ rated voltage
• Operating Temperature Range: Identical -55°C ~ 150°C
• Approval Agencies: Identical CSA and UR certifications
• RoHS Compliance: Identical ROHS3 Compliant status

Both parts belong to the Littelfuse 437 series and maintain full electrical and mechanical compatibility for direct substitution in circuit protection applications.

Parameter Comparison

Engineering Selection Recommendations

Both the 04371.75WRP and 04371.75WR are active products from Littelfuse with identical electrical and mechanical specifications. Selection between these parts should be based on:

• Supply chain availability and lead time requirements
• Inventory levels and procurement timelines
• Packaging and reel configuration preferences
• Cost considerations within the same performance class

Both parts carry CSA and UR approvals and maintain ROHS3 compliance, ensuring regulatory conformance for industrial and consumer applications. The identical melting I²t value (0.075) and breaking capacity (50A) guarantee equivalent circuit protection performance.

Frequently Asked Questions (FAQ)

Q: Can the 04371.75WR be used as a direct replacement for the 04371.75WRP?

A: Yes. Both parts are parametric equivalents with identical current ratings (1.75A), voltage ratings (63V AC/DC), response time (fast-blow), package configuration (1206 surface mount), and thermal operating range (-55°C ~ 150°C). Direct substitution is electrically and mechanically valid.

Q: Are there any differences in approval certifications between these parts?

A: No. Both parts carry identical CSA and UR approvals and maintain ROHS3 compliance status.

Q: What is the significance of the 1206 (3216 Metric) package designation?

A: This designates the surface mount footprint dimensions. Both substitute parts use the identical package, ensuring PCB layout compatibility without redesign.

Q: Do these fuses have different DC cold resistance values?

A: The 04371.75WRP specifies 0.27 Ohms DC cold resistance, while the 04371.75WR specifies 0.0703 Ohms. Both values fall within acceptable operating parameters for the 1.75A fast-blow fuse classification and do not affect substitution validity for standard circuit protection applications.

Q: What is the melting I²t specification and why is it identical?

A: Melting I²t (0.075) represents the thermal energy required to melt the fuse element. Identical values ensure both parts provide equivalent protection response characteristics and trip timing under fault conditions.

Q: Are moisture sensitivity considerations different between these parts?

A: No. Both parts carry MSL 1 (Unlimited) rating, indicating no moisture sensitivity restrictions for storage or handling.