70F274AI-RC Equivalent & Substitute Parts

Part Overview

The 70F274AI-RC is a 270 µH unshielded drum core wirewound inductor manufactured by Bourns Inc., rated for 106 mA maximum current with 13.2Ohm DC resistance. This through-hole axial component operates across -55°C to 105°C and is designed for applications requiring fixed inductance in the 270 µH range at test frequency of 790 kHz.

The 70F274AI-RC is classified as obsolete. Identifying equivalent substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production or repair requirements for systems utilizing this inductor specification.

Substiute Parts

70F274AI-RC

Bourns Inc.In Stock: 126270F274AI-RC Datasheet

Current PartRFQ

B78108S1274J000

EPCOS - TDK ElectronicsIn Stock: 4668B78108S1274J000 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 70F274AI-RC are identified based on the following critical parameters that determine functional equivalence:

• Inductance Value: 270 µH (exact match required)
• Inductance Tolerance: ±5% (matching tolerance specification)
• Core Type: Drum Core, Wirewound (same topology)
• Shielding: Unshielded (same electromagnetic configuration)
• Mounting Type: Through Hole (same assembly method)
• Package: Axial (same form factor)
• Current Rating: Minimum 106 mA (substitute must support or exceed rated current)
• Operating Temperature Range: Must support -55°C ~ 105°C or equivalent
• Compliance: ROHS3 Compliant (regulatory requirement)

The B78108S1274J000 from EPCOS - TDK Electronics meets these substitution criteria with identical inductance, tolerance, core type, shielding, mounting, and package specifications. The substitute provides enhanced current rating (200 mA) and improved DC resistance (5.7Ohm), making it functionally compatible for the 70F274AI-RC application space.

Parameter Comparison

Engineering Selection Recommendations

The B78108S1274J000 is the qualified substitute for the 70F274AI-RC based on the following engineering criteria:

Compliance & Availability: The B78108S1274J000 maintains ROHS3 compliance, matching the regulatory requirement of the original part. As an active product with 4590 units in stock, it provides supply chain continuity compared to the obsolete 70F274AI-RC status.

Electrical Equivalence: Both inductors deliver 270 µH ±5% inductance at test frequencies within 6 kHz of each other (790 kHz vs. 796 kHz), ensuring functional compatibility in circuit applications. The substitute's higher current rating (200 mA vs. 106 mA) and lower DC resistance (5.7Ohm vs. 13.2Ohm) provide performance margin without compromising the original design intent.

Physical Compatibility: Both parts are through-hole axial inductors with identical core topology (drum core, wirewound, unshielded). Dimensional differences (0.170" vs. 0.157" diameter; 0.250" vs. 0.362" length) are within typical PCB layout tolerances for axial components.

Core Material Difference: The substitute uses ferrite core material versus iron in the original. This material change results in improved Q factor (70 vs. 46) and higher self-resonant frequency (2.8MHz vs. 2.5MHz), indicating superior high-frequency performance characteristics.

Frequently Asked Questions (FAQ)

Q: Can the B78108S1274J000 directly replace the 70F274AI-RC in existing designs?

A: Yes. Both inductors share identical inductance (270 µH ±5%), core topology (drum core wirewound), shielding (unshielded), mounting method (through hole), and package format (axial). The substitute meets or exceeds all critical electrical parameters required for functional equivalence.

Q: What is the significance of the different core materials (iron vs. ferrite)?

A: The ferrite core in the B78108S1274J000 delivers higher Q factor (70 vs. 46) and improved self-resonant frequency (2.8MHz vs. 2.5MHz). These characteristics indicate lower losses and better high-frequency performance. For applications operating within the specified frequency range, this represents an enhancement over the original design.

Q: Will the dimensional differences affect PCB layout?

A: The B78108S1274J000 is slightly smaller in diameter (0.157" vs. 0.170") but longer (0.362" vs. 0.250"). Standard through-hole axial component footprints accommodate these variations. Verify PCB hole spacing and clearance for the specific board design, though typical axial layouts support both dimensions.

Q: Is the lower DC resistance of the substitute a concern?

A: No. The B78108S1274J000 exhibits lower DC resistance (5.7Ohm vs. 13.2Ohm), which reduces resistive losses and heat generation. This is a performance improvement that does not compromise circuit function and may enhance overall system efficiency.

Q: Are there any compliance or regulatory differences?

A: Both parts are ROHS3 compliant. The B78108S1274J000 carries REACH Affected status, while the original is REACH Unaffected. Verify REACH compliance requirements for your specific application and end-use region before final selection.

Q: Why is the original part obsolete?

A: The 70F274AI-RC is classified as obsolete by the manufacturer. The B78108S1274J000 is an active product with established supply chain availability, making it the appropriate choice for new designs and ongoing production support.