CMT-8120-B Common Mode Choke Equivalent & Substitute Parts

Part Overview

The CMT-8120-B is a 2-line common mode choke manufactured by Triad Magnetics, designed for power line filtering applications. This through-hole component features a 2.4 mH inductance at 1 kHz with a maximum current rating of 17A and 8mOhm DC resistance. The part is currently active in production and ROHS3 compliant. Substitute parts may be required due to inventory constraints, application-specific current or inductance requirements, or design optimization needs.

Substiute Parts

CMT-8120-B

Triad MagneticsIn Stock: 749CMT-8120-B Datasheet

Current PartRFQ

CMT-8121-B

Triad MagneticsIn Stock: 1146CMT-8121-B Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

The CMT-8121-B is classified as a parametric equivalent to the CMT-8120-B based on the following substitution criteria:

Matching Parameters:

• Manufacturer: Triad Magnetics (same manufacturer)
• Series: CMT (same product family)
• Filter Type: Power Line (identical application category)
• Number of Lines: 2 (identical configuration)
• Voltage Rating - AC: 1500V (1.5kV) (identical)
• Operating Temperature Range: -55°C ~ 105°C (identical)
• Mounting Type: Through Hole (identical)
• Physical Dimensions: 1.700" L x 0.900" W, Height 1.650" (identical)
• Package / Case: Vertical, 4 PC Pin (identical)
• RoHS Status: ROHS3 Compliant (identical)

Differing Parameters:

• Inductance: CMT-8120-B = 2.4 mH; CMT-8121-B = 1 mH
• Current Rating: CMT-8120-B = 17A; CMT-8121-B = 20A
• DC Resistance: CMT-8120-B = 8mOhm; CMT-8121-B = 7mOhm

The CMT-8121-B provides higher current capacity and lower DC resistance, making it suitable for applications where the CMT-8120-B inductance value is not a critical constraint.

Parameter Comparison

Engineering Selection Recommendations

CMT-8120-B Selection Criteria:

• Applications requiring 2.4 mH inductance at 1 kHz
• Current loads up to 17A
• Standard power line filtering with 1500V AC isolation

CMT-8121-B Selection Criteria:

• Applications where 1 mH inductance is acceptable
• Current loads up to 20A
• Enhanced regulatory compliance (CSA, IEC, UL, VDE certifications)
• Lower DC resistance requirement (7mOhm vs 8mOhm)

Both parts maintain identical physical form factor, mounting configuration, and thermal operating range. The CMT-8121-B provides additional regulatory approvals and improved electrical performance in current handling and resistance characteristics. Selection between these parts depends on the specific inductance value required by the application circuit design.

Frequently Asked Questions (FAQ)

Q: Can CMT-8121-B replace CMT-8120-B in all applications?

A: Substitution is valid only if the application circuit design does not require the specific 2.4 mH inductance value of the CMT-8120-B. The CMT-8121-B provides 1 mH inductance, which represents a significant reduction. Circuit performance depends on inductance specification, so verification of application requirements is necessary before substitution.

Q: What are the physical compatibility considerations?

A: Both parts share identical dimensions (1.700" L x 0.900" W, 1.650" height maximum) and package configuration (Vertical, 4 PC Pin through-hole). PCB layout and mounting hole spacing are fully compatible.

Q: How do the electrical characteristics compare?

A: The CMT-8121-B provides higher current capacity (20A vs 17A) and lower DC resistance (7mOhm vs 8mOhm), resulting in reduced power dissipation. The inductance difference (1 mH vs 2.4 mH) is the primary electrical distinction affecting filtering performance.

Q: Are there regulatory compliance differences?

A: The CMT-8121-B includes documented approvals from CSA, IEC, UL, and VDE. The CMT-8120-B approval status is not specified in available documentation. Both parts are ROHS3 compliant and REACH unaffected.

Q: What is the operating temperature range for both parts?

A: Both CMT-8120-B and CMT-8121-B operate across -55°C to 105°C, providing identical thermal performance specifications.

Q: Are there inventory considerations?

A: CMT-8120-B inventory: 641 pieces. CMT-8121-B inventory: 1087 pieces. The CMT-8121-B has higher stock availability.