CMT3-4-R Common Mode Choke Equivalent & Substitute Parts

Part Overview

The CMT3-4-R is a 1.3 mH 2-line common mode choke manufactured by Eaton - Electronics Division, designed for power line filtering applications. This component features a 4A maximum current rating, 32 mOhm typical DC resistance, and through-hole mounting configuration with horizontal pin orientation.

The CMT3-4-R is classified as obsolete. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production or repair requirements for systems utilizing this component.

Substiute Parts

CMT3-4-R

Eaton - Electronics DivisionIn Stock: 907CMT3-4-R Datasheet

Current PartRFQ

SS21V-R300013

KEMETIn Stock: 1602SS21V-R300013 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the CMT3-4-R is evaluated based on the following critical parameters that define functional equivalence in common mode choke applications:

Primary Substitution Criteria:

• Inductance value: 1.3 mH nominal (measured at specified frequency)
• Number of lines: 2-line configuration
• Filter type: Power line filtering
• Mounting type: Through hole
• Physical form factor: 4-pin package

Secondary Compatibility Factors:

• Current rating: Substitute must support minimum 4A operation
• DC resistance: Lower DCR values indicate improved performance characteristics
• Operating temperature range: Substitute must encompass or exceed the required thermal envelope
• Package orientation: Physical dimensions and pin configuration must accommodate board layout constraints

The SS21V-R300013 manufactured by KEMET is identified as a substitute part. While this component shares the same inductance value (1.3 mH), number of lines (2), filter type (power line), and mounting type (through hole), it exhibits differences in current rating (3A versus 4A), DC resistance (70 mOhm versus 32 mOhm), and physical dimensions. These differences establish specific application constraints for substitution.

Parameter Comparison

Engineering Selection Recommendations

CMT3-4-R Status: Obsolete product with 851 units available in current inventory.

SS21V-R300013 Consideration: Active product status with 1,538 units in inventory. ROHS3 compliance provides regulatory alignment for new designs and manufacturing environments with RoHS requirements.

Application-Specific Constraints:

The SS21V-R300013 substitute exhibits a reduced maximum current rating of 3A compared to the CMT3-4-R specification of 4A. This substitution is applicable only in applications where the actual operating current does not exceed 3A. Systems designed for 4A operation require verification that peak and continuous current demands remain below the 3A threshold of the substitute component.

The SS21V-R300013 demonstrates increased DC resistance (70 mOhm versus 32 mOhm typical). This parameter difference results in higher power dissipation and thermal generation during operation. Thermal analysis of the application circuit is required to confirm that the substitute component operates within acceptable temperature limits.

Physical form factor differences exist between the two components. The CMT3-4-R features horizontal pin orientation with dimensions of 25.00 mm x 25.00 mm and 14.00 mm height. The SS21V-R300013 features vertical pin orientation with dimensions of 20.50 mm x 16.50 mm and 24.50 mm height. PCB layout modifications may be necessary to accommodate the different package orientation and height profile.

Operating temperature range of the SS21V-R300013 (-25°C ~ 120°C) is narrower than the CMT3-4-R (-40°C ~ 125°C). Applications requiring operation below -25°C or above 120°C are not compatible with this substitute.

Frequently Asked Questions (FAQ)

Q: Can the SS21V-R300013 directly replace the CMT3-4-R in all applications?

A: No. The SS21V-R300013 has a lower maximum current rating (3A versus 4A) and higher DC resistance (70 mOhm versus 32 mOhm). Substitution is valid only when actual operating current remains below 3A and the increased power dissipation is acceptable within the thermal design of the application.

Q: What are the physical differences between these components?

A: The CMT3-4-R uses horizontal pin orientation with dimensions 25.00 mm x 25.00 mm x 14.00 mm height. The SS21V-R300013 uses vertical pin orientation with dimensions 20.50 mm x 16.50 mm x 24.50 mm height. PCB layout modifications are required for substitution.

Q: How does the increased DC resistance of the SS21V-R300013 affect performance?

A: Higher DC resistance (70 mOhm versus 32 mOhm) increases power dissipation during operation. This results in greater heat generation. Thermal analysis must confirm that the substitute component and surrounding circuit components remain within acceptable operating temperature limits.

Q: Are there compliance differences between these parts?

A: The SS21V-R300013 is ROHS3 compliant, while the CMT3-4-R compliance status is not specified. For applications requiring RoHS compliance, the SS21V-R300013 meets current regulatory requirements.

Q: What is the impact of the different inductance measurement frequencies?

A: The CMT3-4-R inductance is specified at 10 kHz, while the SS21V-R300013 is specified at 1 kHz. Both components provide 1.3 mH nominal inductance. The measurement frequency difference reflects different test standards but does not prevent functional substitution in power line filtering applications.

Q: Can the SS21V-R300013 be used in applications requiring the full -40°C to 125°C temperature range?

A: No. The SS21V-R300013 operating temperature range is -25°C to 120°C. Applications requiring operation below -25°C or above 120°C are not compatible with this substitute.