CMT3-3-R Equivalent & Substitute Parts

Part Overview

The CMT3-3-R is a 2.7 mH common mode choke manufactured by Eaton - Electronics Division, designed for two-line power line filtering applications. This through-hole component is rated for 3A maximum current with a typical DC resistance of 55 mOhm and operates across the temperature range of -40°C to 125°C. The CMT3-3-R is classified as obsolete, making identification of equivalent substitute parts essential for ongoing system support, maintenance, and new design implementations where this component specification is required.

Substiute Parts

CMT3-3-R

Eaton - Electronics DivisionIn Stock: 1154CMT3-3-R Datasheet

Current PartRFQ

7446323003

Würth ElektronikIn Stock: 10077446323003 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the CMT3-3-R is determined by strict equivalence across the following critical electrical and mechanical parameters:

Electrical Equivalence Criteria:

• Inductance value of 2.7 mH at 10 kHz frequency
• Two-line common mode choke configuration
• Maximum current rating of 3A or greater
• DC resistance within acceptable tolerance (55 mOhm typical baseline)
• Operating temperature range of -40°C to 125°C minimum

Mechanical Equivalence Criteria:

• Through-hole mounting technology
• 4-pin package configuration
• Physical dimensions compatible with PCB layout constraints

The substitute part 7446323003 (Würth Elektronik WE-LF series) meets all electrical specifications with identical inductance, line count, current rating, and temperature range. The DC resistance of 60 mOhm represents a 5 mOhm increase from the CMT3-3-R typical value, which remains within acceptable engineering tolerance for common mode choke applications. Both parts utilize through-hole mounting with 4-pin configurations, ensuring mechanical compatibility.

Parameter Comparison

Engineering Selection Recommendations

The CMT3-3-R is classified as obsolete, necessitating transition to active production alternatives. The substitute part 7446323003 from Würth Elektronik provides electrical equivalence across all critical parameters: identical inductance value, line configuration, current rating, and operating temperature range.

Product Status Consideration: The 7446323003 maintains active production status, ensuring long-term availability and supply chain continuity compared to the obsolete CMT3-3-R.

Compliance and Certifications: The 7446323003 is ROHS3 compliant and REACH unaffected, providing regulatory compliance for applications subject to these standards. The CMT3-3-R compliance status is not specified in available documentation.

Physical Configuration Difference: The substitute part features a vertical 4-pin package orientation compared to the horizontal orientation of the CMT3-3-R. This dimensional difference requires PCB layout verification to confirm mechanical fit within existing board designs. The 7446323003 dimensions are 26.50 mm L x 18.50 mm W x 30.50 mm H, compared to the CMT3-3-R dimensions of 25.00 mm L x 25.00 mm W x 14.00 mm H.

DC Resistance Variance: The 7446323003 exhibits a maximum DC resistance of 60 mOhm compared to the CMT3-3-R typical value of 55 mOhm. This 5 mOhm increase is within acceptable tolerance for common mode choke applications and does not compromise functional performance in power line filtering circuits.

Frequently Asked Questions (FAQ)

Q: Can the 7446323003 directly replace the CMT3-3-R in existing designs?

A: Electrical substitution is valid based on identical inductance, current rating, and operating temperature specifications. However, physical layout verification is required due to package orientation differences. The 7446323003 uses vertical pin configuration versus the horizontal configuration of the CMT3-3-R, and height dimensions differ significantly (30.50 mm versus 14.00 mm).

Q: What is the significance of the DC resistance difference between these parts?

A: The CMT3-3-R has a typical DC resistance of 55 mOhm, while the 7446323003 is rated at 60 mOhm maximum. This 5 mOhm variance represents approximately 9% increase and falls within normal manufacturing tolerance ranges for common mode chokes. Power dissipation calculations should account for this difference in high-current applications.

Q: Why is the CMT3-3-R classified as obsolete?

A: Obsolescence indicates the manufacturer has discontinued production. The CMT3-3-R is no longer available through standard distribution channels. The 7446323003 provides functional equivalence with active production status and modern compliance certifications.

Q: Are there compliance differences between these parts?

A: The 7446323003 is certified ROHS3 compliant and REACH unaffected. The CMT3-3-R compliance status is not documented in available specifications. Applications requiring regulatory compliance should utilize the 7446323003 to ensure adherence to current environmental and safety standards.

Q: How do the physical dimensions affect substitution?

A: The CMT3-3-R measures 25.00 mm L x 25.00 mm W x 14.00 mm H in horizontal orientation. The 7446323003 measures 26.50 mm L x 18.50 mm W x 30.50 mm H in vertical orientation. PCB layout must accommodate the increased height and different footprint of the substitute part. Clearance verification is required before implementation.

Q: What packaging differences exist between these parts?

A: The CMT3-3-R is supplied in standard packaging format. The 7446323003 is supplied in tray packaging. This difference affects handling and storage procedures but does not impact electrical or mechanical performance.