ELF-18D225 Common Mode Choke Equivalent & Substitute Parts

Part Overview

The ELF-18D225 is a 6.8 mH, 2-line common mode choke manufactured by Panasonic Electronic Components, designed for through-hole mounting applications with an 800mA current rating. This component is classified as obsolete, making identification of functionally equivalent substitute parts essential for ongoing design support and procurement continuity. The part operates across a temperature range of -20°C to 105°C and is rated for 250V AC applications.

Substiute Parts

ELF-18D225

Panasonic Electronic ComponentsIn Stock: 1129ELF-18D225 Datasheet

Current PartRFQ

7448640401

Würth ElektronikIn Stock: 13557448640401 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the ELF-18D225 is determined by the following critical parameters:

• Inductance Value: 6.8 mH nominal inductance, with measurement frequency tolerance
• Current Rating: Minimum 800mA to support equivalent load handling
• DC Resistance: Maximum acceptable DCR to maintain circuit performance
• Voltage Rating: Minimum 250V AC to meet electrical safety requirements
• Mounting Configuration: Through-hole, vertical orientation with 4-pin package
• Physical Dimensions: Compatible footprint for PCB layout constraints
• Operating Temperature: Support for the required thermal operating window

The substitute part 7448640401 (Würth Elektronik WE-FC series) meets these criteria with equivalent electrical performance and compatible mechanical specifications.

Parameter Comparison

Engineering Selection Recommendations

The 7448640401 (Würth Elektronik WE-FC series) is a direct functional substitute for the obsolete ELF-18D225. Selection rationale is based on the following factors:

Electrical Equivalence: Both parts maintain 6.8 mH inductance and 800mA current rating. The substitute exhibits lower DC resistance (480mOhm vs. 519mOhm), resulting in reduced power dissipation and improved thermal performance.

Compliance Status: The Würth Elektronik part carries active product status with ROHS3 compliance certification, ensuring long-term availability and regulatory alignment. The original Panasonic part is obsolete and subject to supply discontinuation.

Thermal Performance: The substitute supports an extended operating temperature range (-40°C to 125°C) compared to the original (-20°C to 105°C), providing greater design margin for thermal stress conditions.

Mechanical Compatibility: Both parts utilize identical through-hole, vertical 4-pin package configurations. Dimensional differences (21.20mm vs. 20.00mm length; 17.80mm vs. 20.00mm height) are within typical PCB layout tolerances for through-hole components.

Voltage and Frequency Ratings: Both parts are rated for 250V AC operation. The inductance measurement frequency differs (1 kHz vs. 10 kHz), which is standard practice across manufacturers and does not affect functional substitution in typical power line filtering applications.

Frequently Asked Questions (FAQ)

Q: Can the 7448640401 be used as a direct replacement for the ELF-18D225 without PCB modification?

A: Yes. Both parts share identical electrical specifications (6.8 mH, 800mA, 250V AC) and use the same through-hole, vertical 4-pin package configuration. Dimensional variations are minor and fall within standard PCB layout tolerances for through-hole components.

Q: What is the significance of the different inductance measurement frequencies (1 kHz vs. 10 kHz)?

A: Inductance values vary slightly with frequency due to core material characteristics. Both parts are specified at their respective measurement frequencies and deliver equivalent 6.8 mH performance in practical applications. The measurement frequency difference does not affect substitution suitability.

Q: Does the lower DC resistance of the substitute part affect circuit operation?

A: No. Lower DC resistance (480mOhm vs. 519mOhm) is beneficial, reducing power dissipation and heat generation. This represents an improvement over the original specification.

Q: Is the extended temperature range of the substitute part (-40°C to 125°C) a concern?

A: No. The extended range provides additional design margin and is not a limitation. If the original application operates within -20°C to 105°C, the substitute will perform within those bounds with additional headroom.

Q: Are there any compliance or certification differences between the two parts?

A: The substitute part (7448640401) carries ROHS3 compliance certification and active product status. The original part (ELF-18D225) is obsolete. For new designs or long-term procurement, the substitute is the appropriate choice.

Q: What packaging format is the substitute available in?

A: The 7448640401 is supplied in tube packaging, standard for through-hole components. This is compatible with standard PCB assembly processes.