LAL04KB390K Equivalent & Substitute Parts

Part Overview

The LAL04KB390K is a 39 µH unshielded inductor manufactured by Taiyo Yuden, rated for 350 mA maximum current with a DC resistance of 1.12 Ohm maximum. This component is classified as obsolete, necessitating identification of functionally equivalent alternatives for ongoing design requirements and procurement needs. The part operates across a temperature range of -25°C to 105°C and is mounted through-hole in an axial package configuration.

Substiute Parts

LAL04KB390K

Taiyo YudenIn Stock: 686LAL04KB390K Datasheet

Current PartRFQ

1641R-393K

DelevanIn Stock: 10331641R-393K Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LAL04KB390K is based on the following critical parameters that must align between the main part and substitute candidates:

Primary Matching Criteria:

• Inductance value: 39 µH (±10% tolerance)
• Inductance test frequency: 2.5–2.52 MHz
• Mounting type: Through Hole
• Package configuration: Axial

Secondary Compatibility Factors:

• Current rating must meet or exceed the application requirement
• DC resistance must be acceptable for the circuit design
• Operating temperature range must encompass the application environment
• Shielding characteristics (shielded vs. unshielded) may affect electromagnetic compatibility

The substitute part 1641R-393K from Delevan matches the primary inductance specification and mounting configuration. However, differences in current rating, DC resistance, shielding type, and self-resonant frequency must be evaluated against specific circuit requirements.

Parameter Comparison

Engineering Selection Recommendations

The 1641R-393K from Delevan is an active product with current manufacturing status, addressing the obsolescence of the LAL04KB390K. Both components share identical inductance values and tolerances at the same test frequency, with equivalent Q factors at their respective measurement frequencies.

Critical Differences Requiring Circuit Evaluation:

The 1641R-393K exhibits a lower current rating (209 mA versus 350 mA) and higher DC resistance (1.93 Ohm versus 1.12 Ohm). Applications operating at or near the 350 mA specification of the original part cannot use the Delevan substitute without circuit redesign or thermal analysis. The substitute's shielded construction contrasts with the unshielded design of the original part, which may alter electromagnetic coupling characteristics in sensitive circuits.

The Delevan part provides an extended lower temperature operating limit (-55°C versus -25°C), offering broader environmental coverage. The higher self-resonant frequency (29 MHz versus 6.3 MHz) indicates improved high-frequency performance characteristics.

ROHS3 compliance of the 1641R-393K supports regulatory requirements for new designs, whereas the original part's compliance status is not specified.

Frequently Asked Questions (FAQ)

Q: Can the 1641R-393K directly replace the LAL04KB390K in all applications?

A: Direct replacement is not universal. The substitute part has a lower current rating (209 mA maximum versus 350 mA) and higher DC resistance (1.93 Ohm versus 1.12 Ohm). Applications operating above 209 mA or requiring the lower resistance of the original part require circuit modification or alternative sourcing.

Q: What is the impact of shielding differences between these parts?

A: The LAL04KB390K is unshielded while the 1641R-393K is shielded. Shielding reduces electromagnetic radiation and susceptibility to external fields. In circuits sensitive to EMI/RFI, the shielded substitute may alter performance. In circuits requiring minimal shielding effects, the shielded design may introduce unintended coupling changes.

Q: Are the physical dimensions compatible?

A: Both parts are axial through-hole components with similar dimensions (LAL04KB390K: 0.157" Dia × 0.386" L; 1641R-393K: 0.162" Dia × 0.410" L). Minor dimensional differences are within typical PCB layout tolerances for through-hole mounting.

Q: What is the significance of the different self-resonant frequencies?

A: The 1641R-393K has a higher self-resonant frequency (29 MHz versus 6.3 MHz), indicating better performance at higher frequencies before the inductor transitions to capacitive behavior. This difference is relevant only in circuits operating near or above these frequency ranges.

Q: Does the extended temperature range of the 1641R-393K affect compatibility?

A: The Delevan part operates from -55°C to 105°C compared to -25°C to 105°C for the original. The extended lower temperature capability is beneficial for applications in cold environments but does not restrict use in applications within the original temperature range.

Q: Is the 1641R-393K suitable for new designs?

A: The 1641R-393K is an active product with ROHS3 compliance, making it suitable for new designs. However, circuit requirements for current rating and DC resistance must be verified against the substitute's specifications before implementation.