74F686AP-3%-RC Equivalent & Substitute Parts

Part Overview

The 74F686AP-3%-RC is a 6.8 µH unshielded wirewound inductor manufactured by Bourns Inc., rated for 300 mA with a maximum DC resistance of 1.85Ohm. This through-hole axial component operates across -55°C to 125°C and is designed for applications requiring fixed inductance in the microhenry range. The part is classified as obsolete, making identification of equivalent substitutes necessary for ongoing design support and procurement continuity.

Substiute Parts

74F686AP-3%-RC

Bourns Inc.In Stock: 67774F686AP-3%-RC Datasheet

Current PartRFQ

B78108T1682J000

EPCOS - TDK ElectronicsIn Stock: 843B78108T1682J000 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 74F686AP-3%-RC is determined by the following critical parameters:

• Inductance Value: Must be 6.8 µH (exact match required)
• Mounting Type: Must be through-hole axial configuration
• Operating Temperature Range: Must support -55°C ~ 125°C minimum
• Current Rating: Substitute must support at least 300 mA
• DC Resistance: Lower or equal DCR is acceptable; higher values require circuit validation
• Shielding: Unshielded configuration maintained
• Compliance: RoHS3 compliance required

The B78108T1682J000 qualifies as a substitute based on matching inductance, mounting type, temperature range, and compliance requirements. The lower current rating (250 mA vs. 300 mA) and reduced DC resistance (1.45Ohm vs. 1.85Ohm) represent trade-offs that must be evaluated against specific application requirements.

Parameter Comparison

Engineering Selection Recommendations

The B78108T1682J000 is an active production substitute for the obsolete 74F686AP-3%-RC. Both components meet ROHS3 compliance and operate within the required temperature range. The substitute offers improved tolerance (±5% vs. ±10%) and lower DC resistance, which reduces power dissipation in the inductor.

The primary consideration is current rating: the substitute is rated for 250 mA versus the original 300 mA specification. Applications operating at or near 300 mA require verification that the 250 mA rating is sufficient for the intended circuit. The ferrite drum core construction of the substitute differs from the phenolic core of the original, which may affect frequency response characteristics in sensitive applications.

Frequently Asked Questions (FAQ)

Q: Can the B78108T1682J000 be used in all applications where the 74F686AP-3%-RC was specified?

A: Direct substitution is valid for applications operating at 250 mA or below. Applications requiring the full 300 mA rating require circuit-level evaluation to confirm the lower current rating is acceptable.

Q: What is the impact of the different core materials (phenolic vs. ferrite)?

A: Core material affects frequency response and Q factor. The ferrite drum core in the substitute exhibits a Q of 45 at 7.96MHz compared to 50 for the phenolic core original. The self-resonant frequency is also lower (70MHz vs. 75MHz). These differences are minor for most applications but should be verified in frequency-sensitive circuits.

Q: Does the lower DC resistance of the substitute affect circuit operation?

A: Lower DC resistance reduces power dissipation and heat generation, which is generally beneficial. However, if the circuit design relies on the specific impedance characteristics of the 1.85Ohm resistance, the 1.45Ohm value must be validated.

Q: Are the physical dimensions compatible?

A: The substitute is physically smaller (0.130" Dia x 0.276" L vs. 0.200" Dia x 0.500" L). PCB layout and mechanical clearance must be verified before substitution.

Q: What is the inventory status for procurement?

A: The 74F686AP-3%-RC has 617 pieces in stock as new original inventory. The B78108T1682J000 has 792 pieces available as active production stock.