RN242-4-02 Common Mode Choke Equivalent & Substitute Parts

Part Overview

The RN242-4-02 is a 3.3 mH, 2-line common mode choke manufactured by Schaffner EMC Inc., designed for power line filtering applications. This through-hole component is rated for 4A typical current with 66mOhm DC resistance and operates across -40°C to 125°C. The part is currently obsolete, necessitating identification of equivalent alternatives that maintain functional compatibility for power line EMC filtering circuits.

Substiute Parts

RN242-4-02

Schaffner EMC Inc.In Stock: 1240RN242-4-02 Datasheet

Current PartRFQ

RN242-4-02-3M3

Schaffner EMC Inc.In Stock: 1882RN242-4-02-3M3 Datasheet

DirectRFQ

744824433

Würth ElektronikIn Stock: 1169744824433 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the RN242-4-02 is determined by the following critical parameters:

• Inductance Value: 3.3 mH nominal inductance
• Number of Lines: 2-line common mode configuration
• Current Rating: 4A minimum capacity
• Mounting Type: Through-hole vertical orientation with 4-pin configuration
• Voltage Rating: AC voltage withstand capability of 250V or higher
• Operating Temperature Range: Compatibility with -40°C to 125°C or equivalent subset
• Filter Type: Power line EMC filtering application

Two substitute parts meet these criteria with acceptable parameter variations:

1. RN242-4-02-3M3 (Schaffner EMC Inc.): Direct manufacturer alternative with identical mechanical footprint and electrical core specifications
2. 744824433 (Würth Elektronik): Cross-manufacturer equivalent with similar electrical performance and compatible form factor

Parameter Comparison

Engineering Selection Recommendations

RN242-4-02-3M3 is the primary substitute for the obsolete RN242-4-02. Both components are manufactured by Schaffner EMC Inc. within the same RN series, share identical mechanical dimensions and pin configuration, and maintain equivalent electrical performance. The RN242-4-02-3M3 carries active product status with ROHS3 compliance and expanded approval certifications (ENEC, UR, VDE), providing superior long-term availability and regulatory support.

744824433 (Würth Elektronik WE-CMB series) serves as a secondary cross-manufacturer alternative. This part maintains the required 3.3 mH inductance, 4A current rating, and through-hole vertical mounting. The 744824433 exhibits lower DC resistance (35mOhm versus 66mOhm), which reduces power dissipation in the filtering circuit. Mechanical dimensions vary slightly (27.50mm × 18.50mm × 33.00mm versus 31.00mm × 18.00mm × 34.60mm), requiring PCB layout verification. The 744824433 operates across the full -40°C to 125°C temperature range and maintains 250V AC voltage rating.

Selection between RN242-4-02-3M3 and 744824433 depends on PCB space constraints, thermal management requirements, and certification scope. The RN242-4-02-3M3 provides direct form-fit compatibility; the 744824433 offers improved thermal performance through reduced DCR.

Frequently Asked Questions (FAQ)

Q: Can RN242-4-02-3M3 directly replace RN242-4-02 without PCB modification?

A: Yes. Both parts share identical mechanical dimensions (31.00mm × 18.00mm × 34.60mm), vertical 4-pin configuration, and mounting footprint. No PCB layout changes are required.

Q: What is the difference between inductance measured at 1 kHz versus 10 kHz?

A: The RN242-4-02 specifies inductance at 1 kHz, while RN242-4-02-3M3 and 744824433 specify at 10 kHz. Both measurements reflect the same nominal 3.3 mH inductance value; the frequency difference indicates the measurement standard used by each manufacturer. For power line filtering applications, this distinction does not affect functional compatibility.

Q: Is 744824433 suitable for applications requiring VDE or ENEC certification?

A: The 744824433 does not list approval agency certifications. If circuit design requires specific regulatory approvals (VDE, ENEC, UR), the RN242-4-02-3M3 is the appropriate selection, as it carries all three certifications.

Q: How does the lower DCR of 744824433 (35mOhm) affect circuit performance compared to 66mOhm?

A: Lower DC resistance reduces resistive power loss in the choke. For a 4A circuit, the 744824433 dissipates approximately 0.56W versus 1.06W for the RN242-4-02. This improvement reduces thermal stress and may eliminate heatsinking requirements in thermally constrained designs. Electrical filtering performance remains equivalent at the specified 3.3 mH inductance.

Q: Can these parts be used interchangeably in existing designs?

A: RN242-4-02-3M3 is a direct interchange. The 744824433 requires verification of PCB footprint compatibility due to dimensional variations (27.50mm × 18.50mm × 33.00mm). Electrical performance is equivalent for power line filtering applications.

Q: What is the moisture sensitivity level for these components?

A: RN242-4-02 and RN242-4-02-3M3 both carry MSL 1 (Unlimited), indicating no moisture sensitivity. The 744824433 lists MSL as Not Applicable, also indicating no moisture-related handling restrictions.