SF-1206F125-2 Equivalent & Substitute Parts

Part Overview

The SF-1206F125-2 is a 1.25 A surface mount board mount fuse manufactured by Bourns Inc. under the SinglFuse™ SF-1206 series. This component is rated for 63 V DC operation with fast blow response characteristics and is housed in a 1206 (3216 Metric) package format suitable for automated assembly processes. The part maintains active product status with full RoHS3 compliance and UL approval certification. Substitute parts are identified when equivalent electrical ratings, mechanical dimensions, and package specifications align with the original component's functional requirements.

Substiute Parts

SF-1206F125-2

Bourns Inc.In Stock: 1517SF-1206F125-2 Datasheet

Current PartRFQ

04661.25NR

Littelfuse Inc.In Stock: 1037904661.25NR Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

The Littelfuse 04661.25NR qualifies as a direct substitute for the SF-1206F125-2 based on the following alignment of critical parameters:

Current Rating: Both parts are rated at 1.25 A, ensuring identical overcurrent protection thresholds.

Voltage Rating: Both parts support 63 V DC operation, meeting the same electrical stress requirements.

Response Time: Both employ fast blow characteristics, providing equivalent circuit protection response.

Package / Case: Both utilize the 1206 (3216 Metric) surface mount package, enabling direct PCB footprint compatibility.

Mounting Type: Both are surface mount board mount fuses, compatible with identical assembly processes.

Breaking Capacity: Both maintain 50 A breaking capacity at rated voltage, ensuring equivalent fault current handling.

Compliance: Both parts hold RoHS3 compliance and UL certification, satisfying regulatory requirements.

Parameter Comparison

Engineering Selection Recommendations

Both the SF-1206F125-2 and 04661.25NR maintain active product status with full regulatory compliance. The Littelfuse 04661.25NR provides expanded certification coverage through CSA approval in addition to UL certification. Dimensional variations are minimal and within typical manufacturing tolerances for 1206 package components. The DC cold resistance differential (0.088 Ohms versus 0.059 Ohms) reflects design variations between manufacturers but does not affect functional substitution for board mount fuse applications. Operating temperature ranges differ slightly, with the Littelfuse part supporting lower minimum temperatures (-55°C versus -40°C) and the Bourns part supporting higher maximum temperatures (105°C versus 90°C). Selection between these parts depends on specific application temperature requirements and preferred manufacturer availability.

Frequently Asked Questions (FAQ)

Q: Can the Littelfuse 04661.25NR directly replace the Bourns SF-1206F125-2 on existing PCBs?

A: Yes. Both parts share identical 1206 (3216 Metric) package specifications and surface mount footprints, enabling direct PCB substitution without layout modifications.

Q: Are the electrical protection characteristics identical between these two fuses?

A: Both parts provide identical 1.25 A current rating, 63 V DC voltage rating, and 50 A breaking capacity. Fast blow response time is equivalent. The melting I²t values differ slightly (0.062 versus 0.064), representing normal manufacturing variation within the same functional class.

Q: What is the significance of the DC cold resistance difference?

A: The DC cold resistance differential (0.088 Ohms versus 0.059 Ohms) reflects internal element design differences between manufacturers. This parameter does not affect fuse substitution suitability for standard board mount applications.

Q: Do both parts meet the same regulatory requirements?

A: Both parts are RoHS3 compliant with MSL 1 rating. The Littelfuse part carries dual UL and CSA certification, while the Bourns part carries UL certification. Both meet REACH unaffected status and share identical ECCN and HTSUS classifications.

Q: Are there operating temperature constraints for substitution?

A: The Bourns SF-1206F125-2 operates from -40°C to 105°C, while the Littelfuse 04661.25NR operates from -55°C to 90°C. Application temperature requirements must fall within both ranges for unrestricted substitution, or within the overlapping range of -40°C to 90°C for guaranteed compatibility.

Q: What packaging formats are available for these parts?

A: Both parts are supplied in Tape & Reel (TR) format suitable for automated pick-and-place assembly processes.