SCR74B-181 Equivalent & Substitute Parts

Part Overview

The SCR74B-181 is a 180 µH shielded inductor manufactured by Signal Transformer, designed for surface mount applications with a current rating of 870 mA and maximum DC resistance of 1 Ohm. This component is classified as obsolete, making identification of suitable substitute parts essential for ongoing design support and procurement continuity. The part operates across the industrial temperature range of -40°C to 125°C and meets ROHS3 compliance requirements.

Substiute Parts

SCR74B-181

Signal TransformerIn Stock: 1071SCR74B-181 Datasheet

Current PartRFQ

744787181

Würth ElektronikIn Stock: 2819744787181 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SCR74B-181 is determined by the following critical parameters:

• Inductance Value: 180 µH with ±20% tolerance
• Current Rating: Minimum 870 mA to maintain equivalent current handling capability
• DC Resistance: Maximum 1 Ohm to preserve circuit performance
• Shielding: Shielded configuration required for electromagnetic compatibility
• Mounting Type: Surface mount package for PCB compatibility
• Operating Temperature: -40°C to 125°C range
• Compliance: ROHS3 and REACH compliance maintained

The Würth Elektronik 744787181 qualifies as a substitute based on matching inductance value, shielding type, surface mount configuration, and operating temperature range. While the current rating (680 mA) is lower than the original part, the saturation current specification (620 mA) and reduced DC resistance (794 mOhm) provide acceptable electrical characteristics for applications within the 680 mA operating envelope.

Parameter Comparison

Engineering Selection Recommendations

The Würth Elektronik 744787181 is an active product with established supply availability, addressing the obsolescence status of the SCR74B-181. Both parts maintain ROHS3 compliance and identical operating temperature specifications. The substitute part carries AEC-Q200 automotive qualification, providing additional reliability assurance for critical applications.

Selection of the 744787181 is appropriate for applications where the circuit design operates within the 680 mA current envelope. The lower DC resistance of the substitute part (794 mOhm versus 1 Ohm maximum) results in reduced power dissipation, which may provide thermal performance benefits in the application.

Frequently Asked Questions (FAQ)

Q: Can the 744787181 directly replace the SCR74B-181 in all applications?

A: Direct replacement is suitable for applications operating at or below 680 mA. Applications requiring the full 870 mA current rating of the original part require circuit redesign or alternative component selection.

Q: What is the impact of the lower DC resistance in the substitute part?

A: The 794 mOhm maximum DCR of the 744787181 compared to 1 Ohm maximum of the SCR74B-181 results in lower resistive losses and reduced heat generation. This is a favorable characteristic for circuit performance.

Q: Are the physical dimensions compatible?

A: The SCR74B-181 measures 0.327" L x 0.295" W x 0.197" H (8.30mm x 7.50mm x 5.00mm). The 744787181 measures 0.307" L x 0.276" W x 0.177" H (7.80mm x 7.00mm x 4.50mm). Both are surface mount packages with similar footprints suitable for standard PCB layouts, though dimensional verification against specific board designs is necessary.

Q: What compliance certifications apply to the substitute part?

A: The 744787181 maintains ROHS3 compliance, REACH unaffected status, and carries AEC-Q200 automotive qualification. These certifications align with the original part's compliance profile.

Q: How do the saturation current specifications compare?

A: The SCR74B-181 specifies 400 mA saturation current, while the 744787181 specifies 620 mA. The higher saturation current of the substitute part indicates improved performance margin under transient current conditions within its rated operating envelope.