Shielded SMD power inductors
A practical default path for compact buck and boost layouts where EMI control matters.
Power design calculatorBuck mode
Buck / Boost Inductor Selector
Calculate a first-pass inductor value for buck or boost converters from Vin, Vout, load current, switching frequency, and ripple target.
Pick buck or boost, enter the operating point, and the page will estimate the inductance, ripple current, and peak current you need to source against.
Topology snapshot
Translate converter inputs into an inductor target
Operating point
Use idealized operating values for a quick starting point. Final magnetic selection should still be checked against saturation, DCR, thermal rise, and transient behavior.
Calculated target
Buck modeRecommended inductance
20 uH
Buck mode at this operating point suggests about 20 uH, with ripple around 600 mA and peak current near 2.3 A. Use those numbers to shortlist practical stocked inductors.
Duty cycle
50%
Inductor ripple
600 mA
Peak current
2.3 A
Approx. RMS current
2.01 A
Need components for your project? Search parts & check stock instantly.
Turn the magnetic target into part search
Use the estimated inductance and peak current to start a stocked inductor search, then move into RFQ if the shortlist needs sourcing support.
Suggested query
20uH inductor 2.3A shielded power
Escalate to sourcing
Need current margin and package tradeoffs reviewed?
Move into quotation workflows when the magnetic shortlist needs help across stock, alternates, package size, or thermal margin.
Shielded
Low-DCR molded inductors
Useful when current margin and conduction loss are more important than absolute footprint size.
Higher-current drum or composite parts
Helpful when the peak-current estimate pushes beyond small footprint magnetics.
Inductor sizing reference
What does a buck or boost inductor selector calculate?
A buck or boost inductor selector gives a fast starting inductance estimate from operating voltage, current, switching frequency, and ripple-current assumptions. It is useful early in power design when you want to narrow the magnetic range before checking real catalog parts.
In practice, the first-pass inductance value is only one part of the decision. Peak current, RMS current, DC resistance, saturation current, thermal rise, shielding, and package height still decide whether a real inductor is safe for the design.
Core inductor formulas and what they mean
First-pass sizing equations
L = \frac{(V_{in} - V_{out})D}{\Delta I_L f_{sw}}
| Topology | Duty-cycle trend | Ripple target | Practical note |
|---|---|---|---|
| Buck | D decreases as input voltage increases | 20% - 40% of Iout | Lower inductance increases ripple but can reduce size and cost. |
| Boost | D rises as the Vout/Vin ratio increases | 20% - 40% of average inductor current | Peak current can climb quickly, so current margin matters more than the inductance number alone. |
| Both | Check min and max Vin corners | Review transient behavior separately | A single nominal operating point is not enough for final signoff. |
FAQ
Frequently asked questions about buck and boost inductors
Is the calculated inductance enough to choose a real part?
No. It narrows the range, but you still need current rating, saturation margin, DCR, package size, and thermal checks.
What ripple current target should I start with?
A 20% to 40% ripple target is a common first-pass range, then adjusted for transient response, efficiency, and size tradeoffs.
Why does boost mode need extra current attention?
The inductor carries the input-side energy current, so average and peak current can rise substantially above output current.