Bourns 5900-121 120µH Inductor: Equivalent & Substitute Parts

Part Overview

The Bourns 5900-121 is a 120 µH unshielded drum core wirewound inductor rated for 2.1 A continuous current with a maximum DC resistance of 97 mOhm. This through-hole axial component operates across the temperature range of -55°C to 105°C and is designed for applications requiring fixed inductance filtering and energy storage in power conversion circuits.

The 5900-121 carries an obsolete product status. Identifying functionally equivalent substitute parts ensures design continuity and supply chain reliability for legacy system maintenance and new production runs requiring compatible inductance characteristics.

Substiute Parts

5900-121

Bourns Inc.In Stock: 7465900-121 Datasheet

Current PartRFQ

4590-124K

API Delevan Inc.In Stock: 8124590-124K Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the Bourns 5900-121 is determined by the following critical parameters:

• Inductance Value: Must match 120 µH within the specified ±10% tolerance band
• Current Rating: Substitute must support minimum 2.1 A continuous current
• DC Resistance: Substitute DCR must not exceed 97 mOhm to maintain circuit performance
• Core Type & Shielding: Must be ferrite drum core, unshielded construction
• Mounting & Package: Through-hole axial configuration required for PCB compatibility
• Physical Dimensions: Axial package footprint must be compatible with existing board layouts
• Operating Temperature: Substitute must cover the -55°C to 105°C range or equivalent

The API Delevan 4590-124K meets these substitution criteria with matching inductance, compatible current handling, and equivalent thermal performance.

Parameter Comparison

Engineering Selection Recommendations

The API Delevan 4590-124K is a direct functional substitute for the obsolete Bourns 5900-121. Both components share identical inductance values, ferrite drum core construction, and axial through-hole mounting. The 4590-124K provides superior current handling capacity (2.43 A versus 2.1 A) and an extended operating temperature range (-55°C to 125°C versus -55°C to 105°C).

The 4590-124K exhibits a higher maximum DC resistance of 113 mOhm compared to the 5900-121's 97 mOhm specification. This 16 mOhm difference must be evaluated within the context of circuit power dissipation requirements. For applications where DCR-induced losses are critical, thermal analysis of the substitute component is necessary to confirm acceptable performance margins.

Both components carry identical RoHS non-compliance and REACH unaffected certifications. The 4590-124K maintains active product status with confirmed inventory availability, ensuring long-term supply chain continuity.

Frequently Asked Questions (FAQ)

Q: Can the API Delevan 4590-124K directly replace the Bourns 5900-121 in existing designs?

A: Yes, the 4590-124K is a direct substitute. Both components feature 120 µH inductance at ±10% tolerance, ferrite drum core construction, unshielded design, and axial through-hole mounting. Physical dimensions are nearly identical (0.455" versus 0.453" diameter, both 0.900" length), permitting direct PCB footprint compatibility.

Q: What is the impact of the higher DC resistance in the 4590-124K?

A: The 4590-124K specifies 113 mOhm maximum DCR compared to the 5900-121's 97 mOhm maximum. At the rated 2.1 A current, this represents approximately 0.44 mW additional power dissipation per component. Circuit designers must confirm this additional loss remains within acceptable thermal and efficiency budgets for their specific application.

Q: Does the extended temperature range of the 4590-124K provide additional design margin?

A: The 4590-124K operates to 125°C versus the 5900-121's 105°C upper limit. This extended range provides additional thermal margin for applications operating near maximum ambient temperatures or experiencing elevated component self-heating. Designs constrained to the original 105°C specification remain fully compatible with the 4590-124K.

Q: Are there compliance or certification differences between these components?

A: Both components carry identical RoHS non-compliance and REACH unaffected certifications. No compliance advantage exists between the two parts. Applications requiring RoHS-compliant inductors require alternative component selection outside this substitution group.

Q: What is the significance of the 4590-124K's active product status?

A: The 4590-124K maintains active manufacturing status with confirmed inventory availability. The 5900-121 is obsolete. Selecting the 4590-124K ensures continued supply chain access and eliminates the risk of future component unavailability for design revisions or production volume increases.