ELF-18N025A Common Mode Choke Equivalent & Substitute Parts

Part Overview

The ELF-18N025A is a 2-line common mode choke (CMC) manufactured by Panasonic Electronic Components, designed for through-hole mounting applications requiring 2.5A current handling capability. This component is classified as obsolete, making identification of suitable substitute parts essential for ongoing system support and new design implementations. The part features a typical DC resistance of 80mOhm and vertical 4-pin configuration, commonly used in power line filtering and EMI suppression circuits.

Substiute Parts

ELF-18N025A

Panasonic Electronic ComponentsIn Stock: 885ELF-18N025A Datasheet

Current PartRFQ

SS21V-200024

KEMETIn Stock: 2374SS21V-200024 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the ELF-18N025A is determined by the following critical parameters:

Primary Substitution Criteria:

• Number of Lines: 2 (fixed requirement)
• Mounting Type: Through Hole (fixed requirement)
• Package Configuration: Vertical, 4 PC Pin (fixed requirement)
• Current Rating: Minimum 2.0A (acceptable tolerance for 2.5A rated component)
• DC Resistance: Maximum 150mOhm (acceptable operational range)
• Voltage Rating - AC: 250V minimum (for power line applications)

The SS21V-200024 from KEMET meets these substitution criteria as a 2-line through-hole common mode choke with 2A current rating, 150mOhm DCR, and 250V AC voltage rating. The component maintains the same vertical 4-pin configuration and is suitable for equivalent circuit applications.

Parameter Comparison

Engineering Selection Recommendations

The SS21V-200024 serves as a functional substitute for the obsolete ELF-18N025A based on matching core electrical and mechanical specifications. Key considerations for selection:

Product Status: The ELF-18N025A is obsolete with no ongoing manufacturing. The SS21V-200024 maintains active production status, ensuring long-term availability and supply chain continuity.

Compliance: The SS21V-200024 is ROHS3 compliant, addressing modern regulatory requirements. The original ELF-18N025A is RoHS non-compliant, which may present procurement restrictions in certain markets or applications.

Current Rating Differential: The SS21V-200024 is rated at 2.0A versus the original 2.5A rating. This represents a 20% reduction in maximum current capacity. Applications operating at or near the 2.5A limit require thermal and circuit analysis to confirm acceptable operation at the lower rating.

DC Resistance: The SS21V-200024 exhibits 150mOhm DCR compared to the original 80mOhm. This increased resistance results in higher power dissipation and heat generation. Circuit designs sensitive to insertion loss or thermal performance require validation.

Physical Dimensions: The SS21V-200024 is slightly larger in length (20.50mm vs 18.00mm) and narrower in width (16.50mm vs 27.50mm), with reduced height (24.50mm vs 27.50mm). PCB layout modifications may be necessary to accommodate dimensional changes.

Frequently Asked Questions (FAQ)

Q: Can the SS21V-200024 directly replace the ELF-18N025A without circuit modification?

A: Direct pin-compatible replacement is possible due to matching vertical 4-pin through-hole configuration. However, the reduced current rating (2.0A vs 2.5A) and increased DCR (150mOhm vs 80mOhm) require circuit validation. Applications operating below 2.0A with acceptable insertion loss can proceed without modification. Higher current applications or thermally constrained designs require analysis.

Q: What is the impact of increased DC resistance on circuit performance?

A: Increased DCR from 80mOhm to 150mOhm results in higher voltage drop across the component at rated current and increased power dissipation. At 2.0A, the SS21V-200024 dissipates approximately 0.6W compared to 0.32W for the original part. Thermal management and circuit efficiency must be re-evaluated.

Q: Are there dimensional compatibility issues with PCB layouts designed for the ELF-18N025A?

A: The SS21V-200024 has different footprint dimensions. Length increases from 18.00mm to 20.50mm, width decreases from 27.50mm to 16.50mm, and height decreases from 27.50mm to 24.50mm. PCB layouts must be verified for clearance and component placement compatibility.

Q: Does the ROHS3 compliance of the SS21V-200024 affect compatibility with existing assemblies?

A: ROHS3 compliance indicates the substitute part meets current environmental regulations. This does not create incompatibility with existing assemblies. However, mixing RoHS-compliant and non-compliant components in new designs may present supply chain or regulatory challenges.

Q: What is the inductance specification of the SS21V-200024?

A: The SS21V-200024 is specified at 2.4 mH @ 1 kHz. The original ELF-18N025A inductance value is not provided in the available documentation. Inductance matching should be verified if the application has specific filtering or impedance requirements.