Power Electronics

Buck Converter Design Basics

Learn the basics of buck converter duty cycle, inductor selection and ripple current.

What is a buck converter?

A buck converter is a switching regulator that steps down DC voltage with high efficiency.

Duty cycle

For an ideal buck converter, duty cycle is approximately D = Vout / Vin.

Inductor ripple

Inductor value affects ripple current. A common starting point is 20–40% of load current as inductor ripple.

Capacitor and layout

Input and output capacitors reduce ripple and transient effects. PCB layout is critical.

Practical design notes

Always check the regulator datasheet, recommended layout, saturation current and thermal limits.

Use the calculator

Try the related tool and calculate your own values instantly.

Open Buck Converter Calculator