Boost Converter Calculator

Usage Steps

1. Enter target output voltage/current and switching frequency.
2. Select ripple target (ratio) or ΔIL value based on your design goal.
3. Use Vin_min for worst-case duty ratio and current stress.
4. Click Calculate to get L/C sizing and current results.

Model Notes

This calculator uses a CCM boost converter model and evaluates at Vin_min. It estimates ripple-based inductance and capacitance. If IL_min ≤ 0, operation enters DCM and results are approximate.

Design Tips

• When D > 0.9, expect large current stress and higher losses.
• Output capacitor ESR strongly impacts ΔVout; check ripple specs.
• Input capacitor should include 2× margin for transient current.
• Verify inductor and PCB current ratings against IL_pk and IL_rms.

Formula Reference

• Duty ratio: D = 1 - Vin / Vout.
• Power/current: Pout=VoutIout, Pin=Pout/η, Iin,avg=Pin/Vin.
• Ripple target: ΔIL=r·IL,avg, or ΔIL=VinD/(L·fsw).
• Inductance: L = Vin·D / (ΔIL·fsw).
• Current stress: IL,pk=IL,avg+ΔIL/2, IL,rms≈√(IL,avg2+ΔIL2/12), ISW,rms=D·IL,rms, ID,rms=(1-D)·IL,rms.
• Capacitors: Cout≳Iout·D/(ΔVout·fsw), Cin≳Iin·D/(ΔVin·fsw).
• CCM boundary: IL,min=IL,avg-ΔIL/2; if ≤ 0 then DCM. Lcrit=VinD/[2IL,avgfsw].

Results are first-order estimates and do not include parasitics, thermal drift, or control-loop limits.