78FR18M Equivalent & Substitute Parts

Part Overview

The Bourns 78FR18M is a 180 nH unshielded drum core wirewound inductor rated for 450 mA with a maximum DC resistance of 80 mOhm. This through-hole axial component operates across the temperature range of -55°C to 105°C and is designed for applications requiring low inductance values at high frequencies. The 78FR18M is classified as obsolete, making identification of suitable substitute components essential for ongoing design support and production continuity.

Substiute Parts

78FR18M

Bourns Inc.In Stock: 106178FR18M Datasheet

Current PartRFQ

8230-02-RC

Bourns Inc.In Stock: 19548230-02-RC Datasheet

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Key Parameters

Substitute Part Grouping Explanation

The 8230-02-RC from Bourns Inc. qualifies as a substitute for the 78FR18M based on the following critical parameters:

Matching Parameters:

• Inductance value: 180 nH (identical)
• Inductance test frequency: 25 MHz (identical)
• Operating temperature range: -55°C to 105°C (identical)
• Mounting type: Through hole (identical)
• Package type: Axial (identical)
• Shielding: Unshielded (identical)
• Manufacturer: Bourns Inc. (same source)

Allowable Variations:

• Current rating: 450 mA (78FR18M) vs. 1.01 A (8230-02-RC) — higher rating in substitute provides design margin
• DC resistance: 80 mOhm Max (78FR18M) vs. 120 mOhm Max (8230-02-RC) — within acceptable tolerance for low-inductance applications
• Core material: Ferrite (78FR18M) vs. Phenolic (8230-02-RC) — different core construction maintains inductance specification
• Inductance tolerance: ±20% (78FR18M) vs. ±10% (8230-02-RC) — tighter tolerance in substitute
• Physical dimensions: Minor size variation (0.120" Dia x 0.300" L vs. 0.110" Dia x 0.280" L) — compatible with standard through-hole PCB layouts

Parameter Comparison

Engineering Selection Recommendations

The 8230-02-RC is the qualified substitute for the obsolete 78FR18M. Selection of the 8230-02-RC provides the following advantages:

Product Status: The 8230-02-RC maintains active production status, ensuring long-term availability and supply chain continuity compared to the obsolete 78FR18M.

Regulatory Compliance: The 8230-02-RC is ROHS3 compliant, meeting current environmental and regulatory requirements. The 78FR18M is RoHS non-compliant and does not satisfy modern procurement standards.

Electrical Performance: Both components maintain identical inductance values and operating temperature ranges. The 8230-02-RC provides higher current rating capacity (1.01 A vs. 450 mA), offering additional design margin for applications approaching the original current specification.

Physical Compatibility: Both components are through-hole axial packages with minor dimensional differences. Standard PCB layouts accommodate the 8230-02-RC without redesign.

Frequently Asked Questions (FAQ)

Q: Can the 8230-02-RC directly replace the 78FR18M in existing designs?

A: Yes. Both components share identical inductance values (180 nH), inductance test frequency (25 MHz), operating temperature range (-55°C to 105°C), and axial through-hole package configuration. Physical dimensions differ slightly but remain compatible with standard PCB hole spacing.

Q: What is the impact of the higher DC resistance in the 8230-02-RC?

A: The 8230-02-RC has a maximum DC resistance of 120 mOhm compared to 80 mOhm in the 78FR18M. For low-inductance applications, this 40 mOhm difference is typically acceptable. Circuit designers must verify that the increased resistance does not exceed thermal or impedance requirements specific to their application.

Q: Does the different core material affect performance?

A: The 78FR18M uses ferrite core material while the 8230-02-RC uses phenolic core material. Both maintain the specified 180 nH inductance and operate across the same temperature range. The phenolic core in the 8230-02-RC achieves a higher self-resonant frequency (550 MHz vs. 400 MHz), which may provide benefits in high-frequency applications.

Q: Is the tighter inductance tolerance of the 8230-02-RC beneficial?

A: The 8230-02-RC offers ±10% inductance tolerance compared to ±20% for the 78FR18M. Tighter tolerance reduces component variation and may improve circuit performance consistency, particularly in precision RF and high-frequency applications.

Q: What are the compliance implications of switching to the 8230-02-RC?

A: The 8230-02-RC is ROHS3 compliant while the 78FR18M is RoHS non-compliant. For products subject to RoHS regulations or customer requirements, the 8230-02-RC satisfies current environmental compliance standards.

Q: Are there any PCB layout considerations when substituting the 8230-02-RC?

A: The 8230-02-RC is slightly larger (0.120" Dia x 0.300" L vs. 0.110" Dia x 0.280" L). Verify that PCB hole spacing and component clearances accommodate the minor dimensional increase. Standard through-hole spacing typically allows this substitution without layout modification.