Buck converter Calculator

Load current	480 mA
Inductor ripple, peak-to-peak	576 mA
Output ripple, peak-to-peak	14.4 mV

Load current

480 mA

Inductor ripple, peak-to-peak

576 mA

Output ripple, peak-to-peak

14.4 mV

Average inductor current	480 mA
Peak inductor current	768 mA
CCM boundary inductance	60 µH
Output power	2.3 W

Average inductor current

480 mA

Peak inductor current

768 mA

CCM boundary inductance

60 µH

Output power

2.3 W

How buck converter works

The switch connects the supply to L1 during the on interval. The diode carries inductor current during the off interval. C1 smooths the output across R1. These equations describe settled continuous conduction; the guest starts near that operating point.

V_{out}=DV_{in}

Ideal continuous-conduction, open-loop power stage with fixed PWM duty. No feedback controller, switch loss, capacitor ESR or inductor resistance is included in the equations. The guest uses near-ideal switches and diodes. Inputs outside the continuous-conduction or small-ripple range are rejected.

Change the form inputs or click a component value on the schematic. Choose Try in CircuitSim to simulate the configured circuit.

Do the math

Selected input values
V1	12 V
V2 — Switch on-time percentage	40 %
L1	100 µH
R1	10 Ω
C1	100 µF
V2 — Switching frequency	50 kHz

Duty fraction: $D=\text{duty percent}/100$
$40/100$
≈ 0.4
Ideal output: $V_{out}=DV_{in}$
$0.4\times12\,\mathrm{V}$
≈ 4.8 V
Inductor ripple: $\Delta I_L=\frac{(V_{in}-V_{out})D}{L_1f}$
$\frac{2.88\,\mathrm{V}}{100\,\mathrm{\mu H}\times50\,\mathrm{kHz}}$
≈ 576 mA
Peak inductor current: $I_{pk}=I_{L,avg}+\Delta I_L/2$
$480\,\mathrm{mA}+\frac{576\,\mathrm{mA}}{2}$
≈ 768 mA
Output ripple estimate: $\Delta V=\frac{\Delta I_L}{8fC_1}$
$\frac{576\,\mathrm{mA}}{8\times50\,\mathrm{kHz}\times100\,\mathrm{\mu F}}$
≈ 14.4 mV

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Schematic

Results

How buck converter works

Buck converter calculator

Configure

Schematic

Results

How buck converter works

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