78FR82K Equivalent & Substitute Parts

Part Overview

The 78FR82K is a 820 nH unshielded drum core wirewound inductor manufactured by Bourns Inc., rated for 415 mA with a maximum DC resistance of 120 mOhm. This through-hole axial component operates across a temperature range of -55°C to 105°C and is designed for applications requiring low inductance values with controlled impedance characteristics.

The 78FR82K carries an obsolete product status. Identifying equivalent substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production or repair requirements for legacy systems utilizing this component.

Substiute Parts

78FR82K

Bourns Inc.In Stock: 117278FR82K Datasheet

Current PartRFQ

8230-18-RC

Bourns Inc.In Stock: 8268230-18-RC Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 78FR82K is determined by the following critical parameters:

• Inductance Value: Must be 820 nH ±10% to maintain circuit performance
• Current Rating: Substitute must support minimum 415 mA continuous current
• DC Resistance: Lower or equal DCR values are acceptable; higher values may impact circuit efficiency
• Mounting and Package: Through-hole axial configuration required for mechanical compatibility
• Operating Temperature: Must support -55°C to 105°C range
• Shielding Configuration: Unshielded specification must be maintained

The 8230-18-RC from Bourns Inc. meets the core electrical and mechanical substitution criteria, though with specific trade-offs in current rating and DC resistance characteristics.

Parameter Comparison

Engineering Selection Recommendations

The 8230-18-RC serves as an active substitute for the obsolete 78FR82K. Both components share identical inductance values, tolerance specifications, and operating temperature ranges, establishing functional equivalence for the core inductance function.

Key considerations for selection:

Current Rating Differential: The 8230-18-RC is rated for 380 mA versus the 78FR82K's 415 mA. Applications operating at or near the 415 mA threshold require verification that circuit current demands do not exceed 380 mA.

DC Resistance Trade-off: The 8230-18-RC exhibits significantly higher DC resistance (850 mOhm Max versus 120 mOhm Max). This parameter directly affects power dissipation and thermal performance. Circuits sensitive to resistive losses require thermal analysis to confirm acceptable operating conditions.

Quality Factor: The 78FR82K provides superior Q factor performance (40 versus 28 at 25 MHz), indicating lower losses at the test frequency. Applications requiring high-Q characteristics may experience performance degradation with the substitute.

Compliance Status: The 8230-18-RC is ROHS3 compliant and carries active product status, ensuring long-term supply availability and regulatory alignment for new designs or production continuity.

Frequently Asked Questions (FAQ)

Q: Can the 8230-18-RC directly replace the 78FR82K in all applications?

A: Direct replacement is possible only when circuit current requirements do not exceed 380 mA and when the increased DC resistance (850 mOhm versus 120 mOhm) does not create unacceptable power dissipation or thermal conditions. Applications operating near the 415 mA rating or requiring low-loss characteristics require circuit analysis before substitution.

Q: What is the impact of the higher DC resistance in the 8230-18-RC?

A: Higher DC resistance increases resistive losses proportionally to the square of the current flowing through the inductor. In a 380 mA circuit, the 8230-18-RC dissipates approximately 0.123 watts compared to 0.020 watts for the 78FR82K. Thermal management and efficiency requirements must be evaluated for each application.

Q: Are the physical dimensions compatible between these parts?

A: Both components use through-hole axial packaging. The 78FR82K measures 0.110" diameter × 0.280" length, while the 8230-18-RC measures 0.120" diameter × 0.300" length. PCB layout and mechanical clearance must accommodate the slightly larger substitute dimensions.

Q: Does the lower Q factor of the 8230-18-RC affect circuit performance?

A: Q factor indicates energy loss characteristics at specific frequencies. The 8230-18-RC's Q of 28 at 25 MHz versus the 78FR82K's Q of 40 represents approximately 30% higher losses at that frequency. Applications utilizing this frequency range or requiring high selectivity require performance validation.

Q: What is the significance of RoHS compliance status?

A: The 8230-18-RC is ROHS3 compliant, meeting current environmental and regulatory requirements for new product designs and manufacturing. The 78FR82K's non-compliant status may restrict its use in regulated markets or new production environments, making the 8230-18-RC preferable for ongoing supply requirements.