70F394AI-RC Equivalent & Substitute Parts

Part Overview

The 70F394AI-RC is a 390 µH unshielded drum core wirewound inductor manufactured by Bourns Inc., designed for through-hole axial mounting applications. This component features a maximum DC resistance of 15.8Ohm and supports a current rating of 97 mA across an operating temperature range of -55°C to 105°C. The part is classified as obsolete, making identification of suitable equivalent components essential for ongoing system support and new design implementations.

Substiute Parts

70F394AI-RC

Bourns Inc.In Stock: 100370F394AI-RC Datasheet

Current PartRFQ

B78108S1394J000

EPCOS - TDK ElectronicsIn Stock: 29411B78108S1394J000 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 70F394AI-RC is determined by the following critical parameters:

Primary Matching Criteria:

• Inductance value: 390 µH (±5% tolerance maintained)
• Core configuration: Drum core, wirewound construction
• Shielding classification: Unshielded
• Mounting configuration: Through-hole axial package
• Frequency test point: Approximately 790-800 kHz range

Secondary Compatibility Factors:

• Current rating must meet or exceed 97 mA minimum requirement
• DC resistance and self-resonant frequency characteristics within acceptable operating margins
• Compliance certifications: ROHS3 and EAR99 classification maintained

The B78108S1394J000 qualifies as a direct substitute based on matching inductance, core type, shielding, and mounting specifications. Differences in core material (ferrite vs. iron), current capacity, and DC resistance represent performance enhancements rather than incompatibilities.

Parameter Comparison

Engineering Selection Recommendations

The B78108S1394J000 represents a functionally equivalent substitute for the obsolete 70F394AI-RC. Both components maintain identical inductance specifications and core architecture while meeting ROHS3 compliance requirements and EAR99 export classification.

The substitute component offers measurable performance improvements: increased current capacity (180 mA vs. 97 mA), reduced DC resistance (7Ohm vs. 15.8Ohm), and higher quality factor (70 vs. 45 at test frequency). These characteristics position the B78108S1394J000 as a superior alternative for applications requiring the 390 µH inductance specification.

Active product status of the B78108S1394J000 ensures long-term availability and supply chain continuity, addressing the obsolescence constraint of the original component. Physical dimensions differ slightly (0.157" Dia x 0.362" L vs. 0.180" Dia x 0.250" L), requiring verification of mechanical fit within existing PCB layouts and enclosure constraints.

Frequently Asked Questions (FAQ)

Q: Can the B78108S1394J000 directly replace the 70F394AI-RC in existing designs?

A: Yes, from an electrical standpoint. Both components share identical inductance values, tolerance specifications, and core configurations. Mechanical verification is required due to dimensional differences in diameter and length.

Q: What are the key differences between these two inductors?

A: The primary differences are core material (iron vs. ferrite), current rating capacity (97 mA vs. 180 mA), DC resistance (15.8Ohm vs. 7Ohm), and physical dimensions. The substitute provides superior electrical performance characteristics.

Q: Why is the 70F394AI-RC listed as obsolete?

A: Obsolete status indicates the component is no longer manufactured by Bourns Inc. The B78108S1394J000 maintains active production status, ensuring continued availability.

Q: Are there any compliance concerns with substitution?

A: No. Both components maintain ROHS3 compliance and EAR99 classification, ensuring regulatory equivalence for applications subject to these standards.

Q: How do the physical dimensions affect substitution?

A: The B78108S1394J000 measures 0.157" diameter by 0.362" length, compared to 0.180" diameter by 0.250" length for the 70F394AI-RC. PCB layout and enclosure clearances must accommodate the longer axial length of the substitute component.

Q: What is the significance of the higher Q factor in the substitute?

A: The B78108S1394J000 exhibits a Q factor of 70 at 796 kHz versus 45 at 790 kHz for the original component. Higher Q indicates lower energy loss and improved efficiency at the test frequency, representing a performance enhancement.