CMT4-2-R Common Mode Choke Equivalent & Substitute Parts

Part Overview

The CMT4-2-R is a 3.5 mH 2-line common mode choke manufactured by Eaton - Electronics Division, designed for power line filtering applications in through-hole mounting configurations. This component is classified as obsolete, necessitating identification of functionally equivalent substitute parts for ongoing design support and procurement continuity. The part operates across a temperature range of -40°C to 125°C with a maximum current rating of 2.6A and typical DC resistance of 80mOhm.

Substiute Parts

CMT4-2-R

Eaton - Electronics DivisionIn Stock: 1106CMT4-2-R Datasheet

Current PartRFQ

LF2420NP-352

Sumida America Components Inc.In Stock: 1025LF2420NP-352 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the CMT4-2-R are identified based on the following critical parameters that define functional equivalence in common mode choke applications:

Primary Matching Criteria:

• Filter Type: Power Line
• Number of Lines: 2
• Inductance Value: 3.5 mH (measurement frequency may vary)
• Mounting Type: Through Hole
• Package Configuration: Vertical, 4 PC Pin

Secondary Compatibility Factors:

• Current Rating: Substitute must support minimum 2.6A operation
• DC Resistance: Substitute DCR must not exceed design thermal and loss requirements
• Operating Temperature Range: Substitute must cover -40°C ~ 125°C
• Moisture Sensitivity: MSL 1 classification required

The LF2420NP-352 from Sumida America Components Inc. meets the primary matching criteria with identical inductance value (3.5 mH), 2-line configuration, through-hole mounting, and vertical 4-pin package. However, the substitute exhibits reduced current rating (1.7A versus 2.6A) and increased DC resistance (180mOhm versus 80mOhm), which must be evaluated against specific circuit requirements.

Parameter Comparison

Engineering Selection Recommendations

Substitution Feasibility:

The LF2420NP-352 is suitable as a substitute for the obsolete CMT4-2-R in applications where the reduced current rating (1.7A) and increased DC resistance (180mOhm) are compatible with circuit design specifications. The substitute maintains identical inductance value, 2-line configuration, through-hole mounting, and vertical 4-pin package geometry.

Status Advantage:

The LF2420NP-352 carries Active product status, ensuring long-term availability and supply chain continuity compared to the Obsolete CMT4-2-R. The substitute is ROHS3 compliant, providing environmental and regulatory alignment for new designs.

Physical Compatibility:

Both components feature vertical 4-pin through-hole packages with MSL 1 classification. The LF2420NP-352 exhibits slightly different footprint dimensions (0.953" x 0.953" versus 0.984" x 0.606") and reduced height (0.827" versus 1.004"), requiring PCB layout verification to confirm mechanical fit within existing designs.

Electrical Constraints:

Applications operating at or near 2.6A maximum current must evaluate whether the LF2420NP-352's 1.7A rating provides sufficient margin. The doubled DC resistance (180mOhm versus 80mOhm) increases power dissipation and thermal load, requiring thermal analysis in high-current or high-frequency applications.

Frequently Asked Questions (FAQ)

Q: Can the LF2420NP-352 directly replace the CMT4-2-R without circuit modification?

A: Direct replacement is possible only if circuit current requirements do not exceed 1.7A and the increased DC resistance (180mOhm versus 80mOhm) does not violate thermal or loss specifications. PCB layout must accommodate the different footprint dimensions.

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

A: The CMT4-2-R specifies inductance at 10 kHz while the LF2420NP-352 specifies at 1 kHz. Both components provide 3.5 mH nominal inductance, but frequency-dependent behavior may differ. Circuit performance should be validated at actual operating frequencies.

Q: Does the LF2420NP-352's ROHS3 compliance affect compatibility?

A: ROHS3 compliance indicates environmental and regulatory alignment suitable for modern applications. This does not affect electrical or mechanical compatibility with the CMT4-2-R in existing designs.

Q: Are there physical space constraints when substituting the LF2420NP-352?

A: The LF2420NP-352 has a more square footprint (0.953" x 0.953") compared to the CMT4-2-R's rectangular footprint (0.984" x 0.606"), and is shorter (0.827" versus 1.004"). PCB layout verification is required to confirm fit within existing component placement.

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

A: Increased DC resistance from 80mOhm to 180mOhm results in higher power dissipation (I²R losses) and reduced filtering efficiency. Thermal analysis and performance testing are necessary for applications with sustained current flow or high ambient temperatures.

Q: Is the LF2420NP-352 available in the same packaging format?

A: Both components use vertical 4-pin through-hole packages with MSL 1 classification. The LF2420NP-352 is supplied in Bulk packaging, while the CMT4-2-R packaging format is not specified. Verify packaging requirements for procurement and handling procedures.