SC3DF-271 Equivalent & Substitute Parts

Part Overview

The SC3DF-271 is a 270 µH unshielded wirewound surface mount inductor manufactured by Signal Transformer, rated for 240 mA continuous current with a maximum DC resistance of 7.52Ohm. This component is classified as obsolete, making identification of functionally equivalent alternatives necessary 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

SC3DF-271

Signal TransformerIn Stock: 1085SC3DF-271 Datasheet

Current PartRFQ

SDR0703-271KL

Bourns Inc.In Stock: 1104SDR0703-271KL Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SC3DF-271 is determined by the following critical parameters:

• Inductance Value: 270 µH (primary electrical specification)
• Current Rating: Minimum 240 mA to support original circuit requirements
• DC Resistance: Lower DCR values improve efficiency but must not exceed thermal design limits
• Saturation Current: Must support circuit peak current demands
• Mounting Type: Surface mount compatibility required
• Temperature Range: -40°C to 125°C operational envelope
• Compliance: ROHS3 and REACH status for regulatory alignment

The SDR0703-271KL from Bourns Inc. meets these substitution criteria with matching inductance, compatible current ratings, and identical temperature specifications. The substitute exhibits lower DC resistance (3.6Ohm vs 7.52Ohm), improved saturation current performance (220mA vs 120mA), and active product status.

Parameter Comparison

Engineering Selection Recommendations

The SDR0703-271KL is the designated manufacturer-recommended substitute for the SC3DF-271. Selection of this alternative is supported by:

• Regulatory Compliance: Both components maintain ROHS3 and REACH compliance, ensuring continued adherence to environmental standards
• Active Product Status: The SDR0703-271KL is actively manufactured and supported, eliminating obsolescence risk associated with the SC3DF-271
• Electrical Equivalence: Identical 270 µH inductance value at 100 kHz test frequency with tighter tolerance (±10% vs ±20%)
• Thermal Compatibility: Matching -40°C to 125°C operating range ensures thermal design compatibility
• Improved Performance Characteristics: Lower DC resistance (3.6Ohm vs 7.52Ohm) and higher saturation current (220mA vs 120mA) provide enhanced circuit performance

The primary design consideration is the reduced continuous current rating of the SDR0703-271KL (170 mA vs 240 mA). Circuit analysis must confirm that sustained current demands do not exceed 170 mA to ensure reliable operation.

Frequently Asked Questions (FAQ)

Q: Can the SDR0703-271KL directly replace the SC3DF-271 in existing designs?

A: Direct replacement is possible when circuit current requirements do not exceed 170 mA continuous. The SDR0703-271KL maintains identical inductance value, temperature range, and compliance certifications. Verify that peak current demands remain below the 220 mA saturation current specification.

Q: What is the significance of the lower DC resistance in the SDR0703-271KL?

A: The SDR0703-271KL exhibits 3.6Ohm maximum DC resistance compared to 7.52Ohm in the SC3DF-271. This reduction decreases resistive losses and heat generation in the inductor, improving overall circuit efficiency. This characteristic is beneficial in power conversion and filtering applications.

Q: How do the inductance tolerances differ between these parts?

A: The SC3DF-271 specifies ±20% inductance tolerance, while the SDR0703-271KL provides ±10% tolerance. The tighter tolerance of the substitute part reduces inductance variation across production batches, improving circuit performance consistency and reducing design margin requirements.

Q: Are there packaging differences between these inductors?

A: Both components are surface mount inductors with similar physical dimensions (6.50mm L x 4.40mm W for SC3DF-271; 6.50mm L x 4.50mm W for SDR0703-271KL). The SDR0703-271KL is supplied in Tape & Reel packaging, while the SC3DF-271 packaging format is nonstandard. Both maintain MSL 1 (Unlimited) moisture sensitivity classification.

Q: What is the saturation current specification and why does it matter?

A: Saturation current (Isat) represents the current level at which the inductor's magnetic core begins to saturate, causing inductance to degrade. The SDR0703-271KL provides superior saturation performance (220mA vs 120mA), allowing operation at higher peak currents without inductance collapse. This is critical in switching power supplies and transient-rich applications.