SCMS5D18-221 Equivalent & Substitute Parts

Part Overview

The SCMS5D18-221 is a 220 µH shielded surface mount inductor manufactured by Signal Transformer, rated for 290 mA with a maximum DC resistance of 4.37Ohm. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity. The part operates across the temperature range of -40°C to 125°C and is ROHS3 compliant.

Substiute Parts

SCMS5D18-221

Signal TransformerIn Stock: 902SCMS5D18-221 Datasheet

Current PartRFQ

SCMS5D25-221

Signal TransformerIn Stock: 1064SCMS5D25-221 Datasheet

MFR RecommendedRFQ

SD14-221-R

Eaton - Electronics DivisionIn Stock: 1010SD14-221-R Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SCMS5D18-221 is determined by the following critical parameters:

• Inductance value: 220 µH (±20% tolerance)
• Inductance test frequency: 100 kHz
• Shielding: Shielded construction required
• Mounting type: Surface Mount
• Physical footprint: 0.205" L x 0.205" W (5.20mm x 5.20mm)
• Operating temperature range: Minimum -40°C ~ 125°C or compatible subset
• Current rating: Equal to or greater than 290 mA
• DC resistance: Lower or equal values preferred for thermal performance

Two substitute parts meet these criteria: the SCMS5D25-221 from Signal Transformer and the SD14-221-R from Eaton - Electronics Division. Both maintain the core inductance specification, shielding requirement, and footprint dimensions while offering improved electrical characteristics or active product status.

Parameter Comparison

Engineering Selection Recommendations

SCMS5D25-221 is the primary substitute for the SCMS5D18-221. Both components are manufactured by Signal Transformer and share identical inductance, tolerance, shielding, footprint, and operating temperature specifications. The SCMS5D25-221 offers superior electrical performance with a 400 mA current rating (versus 290 mA) and reduced DC resistance of 2.1Ohm (versus 4.37Ohm), resulting in lower power dissipation. The SCMS5D25-221 maintains active product status, ensuring long-term availability and supply chain continuity. The increased height of 0.110" (2.80mm) versus 0.075" (1.90mm) must be evaluated for PCB layout compatibility.

SD14-221-R from Eaton - Electronics Division is an alternative substitute with active product status. This component maintains the 220 µH inductance, ±20% tolerance, shielding, and footprint dimensions. The SD14-221-R features a drum core, wirewound construction with ferrite core material and offers the lowest seated height of 0.057" (1.45mm). The current rating of 258 mA is lower than the main part, and the operating temperature range is limited to -40°C ~ 85°C. Selection of this part requires confirmation that the reduced temperature ceiling and current rating are acceptable for the application.

Frequently Asked Questions (FAQ)

Q: Can SCMS5D25-221 be used as a direct replacement for SCMS5D18-221?

A: The SCMS5D25-221 is electrically compatible as a substitute. Both parts maintain 220 µH inductance at ±20% tolerance, identical shielding, footprint dimensions (5.20mm x 5.20mm), and operating temperature range (-40°C ~ 125°C). The SCMS5D25-221 provides improved current handling (400 mA versus 290 mA) and lower DC resistance (2.1Ohm versus 4.37Ohm). PCB layout must accommodate the increased height of 2.80mm versus 1.90mm.

Q: What are the key differences between the two substitute parts?

A: SCMS5D25-221 is from Signal Transformer with higher current rating (400 mA) and lower DC resistance (2.1Ohm), but greater height (2.80mm). SD14-221-R is from Eaton with lower current rating (258 mA), lower height (1.45mm), and a more limited operating temperature range (-40°C ~ 85°C). Both maintain the 220 µH inductance and 5.20mm x 5.20mm footprint.

Q: Are there any compliance or regulatory differences between these parts?

A: SCMS5D18-221 and SCMS5D25-221 are both ROHS3 compliant. SD14-221-R is RoHS compliant. All three parts are REACH unaffected and classified under ECCN EAR99. Moisture sensitivity level is 1 (Unlimited) for all parts.

Q: Does the height difference affect PCB assembly?

A: Yes. SCMS5D25-221 has a seated height of 2.80mm compared to 1.90mm for the original part, representing a 0.90mm increase. SD14-221-R has the lowest height at 1.45mm. Height differences must be evaluated against PCB clearance requirements, component stacking, and enclosure constraints.

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

A: Saturation current (Isat) indicates the current level at which the inductor begins to lose inductance due to core saturation. SCMS5D18-221 has Isat of 217 mA, SCMS5D25-221 has 220 mA, and SD14-221-R has 249 mA. For applications operating near the rated current, saturation current must remain above the maximum expected circuit current to maintain inductance stability.