HM78D-128680MLFTR

Overview

The HM78D-128680MLFTR is a shielded surface-mount coupled inductor array manufactured by TT Electronics/BI Magnetics. It features two coils with an inductance of 68 µH when connected in parallel and 272 µH in series. The component has a tolerance of ±20% and operates within a temperature range of -40°C to +125°C. Key electrical specifications include a maximum DC current rating of 2.6 A for parallel connections and 1.3 A for series configurations. The DC resistance is 105 mΩ in parallel and 420 mΩ in series, with saturation currents of 4.1 A (parallel) and 2.1 A (series).

Feature Summary

• Dual-coil architecture providing flexible series or parallel connectivity options.
• Shielded construction designed to minimize electromagnetic interference.
• Surface-mount package optimized for automated assembly processes.

Applications

• DC-DC converter output filtering stages.
• Power supply input/output common-mode noise suppression.
• Multi-phase power distribution networks.

Procurement Notes

Verify the specific suffix and tape/reel configuration against the manufacturer's latest datasheet before ordering. Confirm that the required inductance value matches the intended circuit topology, as the device offers distinct values for series and parallel connections. Ensure the selected packaging format aligns with available surface-mount placement equipment capabilities.

Selection Notes

Select this component when dual independent or coupled inductors are required in a compact footprint. Evaluate the saturation current requirements carefully, noting the difference between parallel and series operation modes. Consider the thermal performance at the specified maximum operating temperature of 125°C during high-current applications.

Part Context

This part belongs to the HM78D series of surface-mount coupled inductors from TT Electronics/BI Magnetics. The series is characterized by shielded designs suitable for dense PCB layouts. The model number indicates specific electrical parameters and physical dimensions consistent with the 12.5 mm x 12.5 mm form factor.

Replacement Considerations

SRF1280-680M by Bourns Inc. is listed as a substitute option. Verify mechanical compatibility and electrical equivalence before implementation.

FAQ

What is the difference in inductance between series and parallel connections?

The inductance is 272 µH when the coils are connected in series and 68 µH when connected in parallel.

What is the maximum operating temperature for this component?

The component is rated for a maximum operating temperature of +125°C.