Power Inductor Selection Guide for DC-DC Converters

The power inductor is often the single most impactful component in a buck or boost converter. Choosing the right one affects efficiency, ripple, and overall board size.

Key parameters to evaluate

1. Inductance value: sets the ripple current. Too low means high ripple; too high slows transient response.
2. Saturation current (Isat): the inductor must not saturate at peak current, or performance collapses.
3. DC resistance (DCR): directly drives copper loss; lower DCR means higher efficiency.
4. Self-resonant frequency (SRF): keep the switching frequency well below SRF.

Practical tips

• Allow a 20-30% headroom on Isat over the worst-case peak current.
• For high-frequency converters, molded inductors offer lower EMI and better thermal performance.
• Always verify temperature rise in the final layout.

ANFULLY offers shielded, molded and low-profile inductors with full electrical characterization, plus free samples for evaluation.

This article was written by fifi. Reproduction with attribution is welcome.