Boost Converter Calculator

Model converter performance with practical electrical inputs. Size inductors, capacitors, and switching stress values. Improve regulated power designs using fast, accurate engineering estimates.

Calculator Inputs

Performance Graph

The graph shows one simplified inductor current cycle using the calculated valley and peak values.

Example Data Table

Case Vin (V) Vout (V) Iout (A) Freq (kHz) Efficiency (%) Duty Approx.
Battery Lift 5 12 1.5 250 90 0.58
Industrial Rail 12 24 2.0 100 92 0.50
Solar Step-Up 18 48 3.0 75 94 0.63
Portable Device 3.7 9 0.8 500 88 0.59

Formula Used

Ideal boost voltage gain: Vout = Vin / (1 - D)

Ideal duty cycle: D = 1 - Vin / Vout

Practical duty estimate: D ≈ 1 - (Vin - Vswitch) / (Vout + Vdiode)

Output power: Pout = Vout × Iout

Input power: Pin = Pout / η

Input current: Iin = Pin / Vin

Required inductance: L = Vin × D / (ΔIL × fs)

Required output capacitance: C = Iout × D / (fs × ΔVout)

Critical inductance: Lcrit = D × (1 - D)² × R / (2 × fs)

These equations provide engineering estimates for sizing and stress checks. Real designs should also consider ESR, switching losses, core losses, transient response, controller behavior, and component derating.

How to Use This Calculator

  1. Enter the source voltage, desired output voltage, and load current.
  2. Set switching frequency and estimated efficiency for realistic results.
  3. Provide diode and switch voltage drops for non-ideal operation.
  4. Choose ripple targets for the inductor current and output voltage.
  5. Optionally enter actual inductor and capacitor values to test them.
  6. Click Calculate Converter to display results above the form.
  7. Review duty cycle, current stress, ripple, CCM/DCM indication, and power loss.
  8. Download the result set as CSV or PDF for documentation.

Frequently Asked Questions

1. What does a boost converter do?

A boost converter increases a lower DC input voltage to a higher DC output voltage. It stores energy in an inductor during switch on-time and releases it to the load during off-time.

2. Why is duty cycle important?

Duty cycle controls how long the switch stays on during each cycle. Higher duty cycles generally raise the output voltage, but they also increase current stress and design sensitivity.

3. Why are practical results different from ideal equations?

Real converters include diode drops, switch losses, ESR, inductor resistance, dead time, and control losses. Ideal formulas are useful for estimates, but practical design always needs margin.

4. What is inductor ripple current?

Inductor ripple current is the change in inductor current within one switching cycle. It affects peak current, thermal stress, efficiency, and whether the converter remains in continuous conduction.

5. How do I choose switching frequency?

Higher frequency can reduce inductor and capacitor size, but it often increases switching losses and EMI. Choose a value that balances size, efficiency, thermal limits, and controller capability.

6. What does CCM or DCM mean?

CCM means inductor current never reaches zero during normal operation. DCM means it does. This changes gain behavior, stress, control response, and component selection assumptions.

7. Why check switch and diode stress?

Semiconductors must survive both voltage and current stress with proper safety margin. Underestimating these values can cause overheating, reduced lifetime, or immediate device failure.

8. Can I use this for final hardware release?

This tool is best for preliminary engineering calculations. Final hardware should still be verified with datasheets, thermal modeling, control-loop analysis, PCB parasitics, and laboratory testing.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.