SPD127-124M Equivalent & Substitute Parts Reference

Part Overview

The SPD127-124M is a 120 µH shielded drum core wirewound inductor manufactured by API Delevan Inc., rated for 1.6 A continuous current with a maximum DC resistance of 250 mOhm. This surface mount component operates across the temperature range of -55°C to 125°C and is designed for applications requiring fixed inductance in compact nonstandard packages.

The SPD127-124M is classified as obsolete. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production requirements for systems utilizing this inductor specification.

Substiute Parts

SPD127-124M

API Delevan Inc.In Stock: 874SPD127-124M Datasheet

Current PartRFQ

HRSPD127-124M

API Delevan Inc.In Stock: 1173HRSPD127-124M Datasheet

DirectRFQ

SCRH127-121

Signal TransformerIn Stock: 732SCRH127-121 Datasheet

SimilarRFQ

SRR1208-121YL

Bourns Inc.In Stock: 2055SRR1208-121YL Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SPD127-124M are identified based on the following critical parameters that determine functional equivalence:

Primary Matching Criteria:

• Inductance value: 120 µH (fixed requirement)
• Inductance tolerance: ±20% or tighter
• Current rating: minimum 1.6 A
• DC resistance: maximum 250 mOhm
• Shielding: shielded construction
• Core material: ferrite
• Mounting type: surface mount
• Operating temperature range: minimum -55°C to 125°C coverage

Substitution Logic: Parts are grouped as direct equivalents or similar alternatives based on adherence to these parameters. Direct equivalents maintain all critical specifications within the original tolerances. Similar alternatives meet the functional requirements but may vary in secondary characteristics such as saturation current, package dimensions, or compliance certifications.

Parameter Comparison

Engineering Selection Recommendations

HRSPD127-124M (Direct Equivalent - Recommended Primary Substitute)

The HRSPD127-124M is the direct equivalent from the same manufacturer, API Delevan Inc. It maintains identical inductance (120 µH), tolerance (±20%), and current rating (1.6 A) specifications. The DC resistance is improved at 201 mOhm maximum compared to 250 mOhm, providing lower losses. The operating temperature range extends to 130°C, offering broader thermal coverage. This part is active in production and available in higher inventory quantities (1144 pcs). However, it remains RoHS non-compliant, matching the original part's compliance status. Physical dimensions are nearly identical with minimal height increase (9.02 mm vs. 8.00 mm).

SCRH127-121 (Similar Alternative - RoHS3 Compliant)

The SCRH127-121 from Signal Transformer meets all critical functional requirements with 120 µH inductance, ±20% tolerance, and 250 mOhm DC resistance matching the original specification. The current rating is slightly higher at 1.7 A, providing additional margin. This part is ROHS3 compliant, addressing environmental regulatory requirements. The operating temperature range is -40°C to 125°C, which covers the upper specification but does not extend to the -55°C lower limit. Physical dimensions are slightly larger (12.50 × 12.50 × 8.00 mm). Selection of this part requires confirmation that the -40°C minimum temperature is acceptable for the application.

SRR1208-121YL (Similar Alternative - Enhanced Performance)

The SRR1208-121YL from Bourns Inc. provides 120 µH inductance with tighter tolerance (±15%), lower DC resistance (190 mOhm maximum), and improved saturation current (2.0 A). This part is ROHS3 compliant and active in production with the highest inventory availability (1987 pcs). The current rating is 1.4 A, which is below the original 1.6 A specification and requires application verification. The operating temperature range is -40°C to 125°C, not extending to -55°C. Physical dimensions are the largest of the group (12.70 × 12.70 × 8.50 mm). This part is suitable for applications where the lower current rating is acceptable and the -40°C minimum temperature is sufficient.

Frequently Asked Questions (FAQ)

Q: Can HRSPD127-124M directly replace SPD127-124M without design changes?

A: Yes. The HRSPD127-124M is a direct equivalent with identical inductance (120 µH), tolerance (±20%), and current rating (1.6 A). The improved DC resistance (201 mOhm vs. 250 mOhm) and extended temperature range (-55°C to 130°C) provide performance benefits. Physical dimensions are nearly identical. No design changes are required.

Q: What is the impact of the lower current rating in SRR1208-121YL?

A: The SRR1208-121YL has a current rating of 1.4 A compared to the original 1.6 A specification. This part is suitable only if the application's actual current draw does not exceed 1.4 A. Verify the circuit's maximum operating current before selection.

Q: Why do SCRH127-121 and SRR1208-121YL have a -40°C minimum temperature instead of -55°C?

A: These parts are specified with a -40°C minimum operating temperature. Applications requiring operation below -40°C must use HRSPD127-124M or the original SPD127-124M. Verify the application's minimum operating temperature requirement before selection.

Q: Are there RoHS compliance differences between the substitute parts?

A: Yes. SPD127-124M and HRSPD127-124M are RoHS non-compliant. SCRH127-121 and SRR1208-121YL are ROHS3 compliant. If RoHS compliance is a design requirement, select SCRH127-121 or SRR1208-121YL, subject to temperature and current rating verification.

Q: How do DC resistance differences affect circuit performance?

A: Lower DC resistance reduces power dissipation and heat generation. HRSPD127-124M (201 mOhm) and SRR1208-121YL (190 mOhm) dissipate less power than SPD127-124M and SCRH127-121 (both 250 mOhm). For applications sensitive to inductor losses, the lower resistance alternatives provide improved efficiency.

Q: Are the physical dimension differences significant for PCB layout?

A: All substitute parts are nonstandard packages with dimensions within 12.00 to 12.70 mm length and width, and 8.00 to 9.02 mm height. Verify that the specific footprint and height clearance of the selected part are compatible with the PCB layout and assembly process before implementation.

Q: What is the difference between "Direct Equivalent" and "Similar Alternative"?

A: Direct equivalents (HRSPD127-124M) maintain all critical specifications of the original part. Similar alternatives (SCRH127-121, SRR1208-121YL) meet functional requirements but vary in secondary characteristics such as current rating, temperature range, or compliance status. Verify all parameters against application requirements before selecting a similar alternative.