Würth Elektronik 744045391 Equivalent & Substitute Parts

Part Overview

The Würth Elektronik 744045391 is a 390 µH unshielded drum core wirewound inductor rated for 110 mA continuous current with a maximum DC resistance of 13 Ohm. This surface mount component operates across the temperature range of -40°C to 125°C and is designed for applications requiring stable inductance in the microhenry range. The part is currently active in production and ROHS3 compliant. Substitute parts are identified when equivalent inductance values, core materials, and operating temperature ranges align with the original specification, enabling component interchangeability in circuit designs where the primary electrical characteristics remain constant.

Substiute Parts

744045391

Würth ElektronikIn Stock: 1335744045391 Datasheet

Current PartRFQ

SDR0403-391KL

Bourns Inc.In Stock: 2958SDR0403-391KL Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 744045391 is determined by the following critical parameters:

• Inductance Value: Must be 390 µH with ±10% tolerance
• Core Material: Ferrite drum core construction
• Shielding Configuration: Unshielded design
• Operating Temperature Range: -40°C to 125°C minimum
• Mounting Technology: Surface mount configuration
• RoHS Compliance: ROHS3 compliant status

The Bourns SDR0403-391KL meets these primary electrical and environmental criteria. While secondary parameters such as current rating, DC resistance, and package dimensions differ, the core inductance specification and material composition remain equivalent, permitting functional substitution in applications where the 110 mA current rating of the original part is not exceeded by circuit requirements.

Parameter Comparison

Engineering Selection Recommendations

Both the Würth Elektronik 744045391 and Bourns SDR0403-391KL are active production components with ROHS3 compliance and REACH unaffected status, meeting current regulatory requirements for electronic component manufacturing and distribution.

The Würth part operates at a specified current rating of 110 mA with a saturation current of 270 mA. The Bourns substitute provides a higher current rating of 150 mA with a saturation current of 220 mA, making it suitable for applications operating within the 110 mA envelope of the original specification.

The Würth part exhibits a maximum DC resistance of 13 Ohm, while the Bourns substitute provides lower DC resistance at 6.4 Ohm maximum. This difference results in reduced power dissipation in the Bourns component under equivalent current conditions.

Both components maintain identical inductance values, tolerance specifications, core materials, shielding configurations, and operating temperature ranges. Selection between these parts should be based on circuit current requirements, acceptable power dissipation levels, and physical space constraints within the application.

Frequently Asked Questions (FAQ)

Q: Can the Bourns SDR0403-391KL directly replace the Würth 744045391 in all applications?

A: The Bourns part meets the core electrical specifications of 390 µH inductance with ±10% tolerance and operates across the same temperature range. Substitution is valid for applications where circuit current does not exceed 110 mA, the original design current rating. The lower DC resistance of the Bourns part may provide operational benefits in terms of reduced heat generation.

Q: What are the physical dimension differences between these parts?

A: The Würth 744045391 is packaged in the 1812 (4532 Metric) standard with dimensions of 4.50mm L x 3.20mm W and a maximum seated height of 2.90mm. The Bourns SDR0403-391KL uses a nonstandard package measuring 4.50mm L x 4.00mm W with a maximum seated height of 4.60mm. The increased width and height of the Bourns part must be evaluated against available PCB layout space.

Q: Are both parts suitable for high-temperature applications?

A: Both components are rated for operation from -40°C to 125°C, meeting identical environmental specifications. Both maintain ROHS3 compliance and unlimited moisture sensitivity level (MSL 1), indicating no special storage or handling requirements.

Q: How do the saturation current specifications affect substitution?

A: The Würth part saturates at 270 mA while the Bourns part saturates at 220 mA. For applications operating at or near the 110 mA design current, both parts provide adequate saturation margin. The Bourns part's lower saturation current should be considered if circuit transients or fault conditions could drive current above 220 mA.

Q: What is the significance of the different Q factors listed for each part?

A: The Würth part specifies Q of 50 at 796 kHz, while the Bourns part specifies Q of 40 at the same frequency. This parameter was provided in the source data but does not alter the substitution determination, as both parts maintain the required 390 µH inductance specification across their operating ranges.