Equivalent & Substitute Parts for C1S 4 Surface Mount Fuse

Part Overview

The C1S 4 is a 4A 63V AC/DC board mount surface mount fuse in 1206 (3216 Metric) package manufactured by Bel Fuse Inc. This component is classified as obsolete, making identification of active equivalent parts essential for ongoing design support and procurement. The substitute part 0685T4000-01 provides functional equivalence with improved availability and active product status.

Substiute Parts

C1S 4

Bel Fuse Inc.In Stock: 1047C1S 4 Datasheet

Current PartRFQ

0685T4000-01

Bel Fuse Inc.In Stock: 1129760685T4000-01 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

The substitute part 0685T4000-01 qualifies as a direct equivalent based on the following critical parameters:

• Current Rating: 4 A (identical)
• Voltage Rating AC/DC: 63 V / 63 V (identical)
• Response Time: Slow Blow (identical)
• Package / Case: 1206 (3216 Metric) (identical)
• Mounting Type: Surface Mount (identical)
• Fuse Type: Board Mount (Cartridge Style Excluded) (identical)
• Breaking Capacity @ Rated Voltage: 50 A (identical)
• Operating Temperature Range: -55°C to 125°C (identical)

The substitute part maintains all electrical and mechanical specifications required for direct board-level replacement. Physical dimensions show a minor height variation (0.023" vs 0.025"), which remains within standard PCB assembly tolerances for 1206 surface mount components.

Parameter Comparison

Engineering Selection Recommendations

The 0685T4000-01 is the appropriate selection for new designs and ongoing production requiring a 4A 63V AC/DC slow blow surface mount fuse in 1206 package. This part maintains active product status with Bel Fuse Inc., ensuring long-term availability and supply chain stability. Both parts carry identical regulatory compliance certifications (CE, cURus) and RoHS3 compliance. The substitute part includes AEC-Q200 qualification, providing additional automotive-grade reliability assurance. DC cold resistance values (0.032 Ohms vs 0.03 Ohms) are functionally equivalent for circuit protection applications. Packaging availability in Tape & Reel format for the substitute part supports high-volume manufacturing requirements.

Frequently Asked Questions (FAQ)

Q: Can 0685T4000-01 be used as a direct replacement for C1S 4 in existing designs?

A: Yes. Both parts share identical electrical ratings (4A, 63V AC/DC), response time (Slow Blow), package (1206), and mounting type (Surface Mount). Physical dimensions are within standard PCB assembly tolerances.

Q: What is the difference in DC cold resistance between these parts?

A: C1S 4 has 0.032 Ohms while 0685T4000-01 has 0.03 Ohms. This 0.002 Ohm difference is negligible for fuse circuit protection applications and does not affect functional equivalence.

Q: Why is C1S 4 marked as obsolete?

A: Obsolete status indicates the part is no longer in active production. The 0685T4000-01 (C1T series) is the active equivalent from the same manufacturer.

Q: Are there packaging differences between these parts?

A: C1S 4 packaging is not specified in available data. 0685T4000-01 is supplied in Tape & Reel (TR) format, standard for high-volume surface mount assembly.

Q: Do both parts meet the same regulatory standards?

A: Both parts are CE and cURus approved, ROHS3 compliant, and REACH unaffected. The substitute part additionally carries AEC-Q200 automotive qualification.

Q: Can these parts be used interchangeably in automotive applications?

A: 0685T4000-01 carries AEC-Q200 qualification, making it suitable for automotive use. C1S 4 does not list this certification.