Half Bridge Converter Calculator

Model voltage, current, ripple, and sizing instantly. Review practical converter behavior with clear design outputs today.

Calculator Inputs

Example Data Table

Vin (V) Duty Ns/Np Freq (kHz) Load (Ohm) Eff (%) Estimated Vout (V)
325 0.35 0.18 100 4 92 17.431
48 0.40 0.50 80 6 90 7.240
380 0.30 0.12 120 8 94 11.462

Formula Used

Primary half-bus voltage: Vpri,half = Vin / 2

Secondary applied voltage: Vsec = (Vin / 2) × (Ns / Np)

Ideal output voltage: Vout,ideal = D × (Ns / Np) × Vin

Estimated output voltage: Vout = (Vout,ideal × η) − 2Vd

Output current: Iout = Vout / Rload

Output power: Pout = Vout × Iout

Input power: Pin = Pout / η

Input current: Iin = Pin / Vin

Effective output ripple frequency: fripple = 2 × fs

Inductor ripple current target: ΔI = Iout × ripple%

Required output inductance: L = [(Vsec − Vout) × D] / [ΔI × 2fs]

Required output capacitance: C = ΔI / [8 × 2fs × ΔV]

These relations suit fast design estimation for a practical isolated half bridge stage. Final magnetics, rectifier topology, dead time, ESR, control loop, and current mode effects require deeper verification.

How to Use This Calculator

  1. Enter the DC input voltage feeding the half bridge stage.
  2. Set duty cycle for each switch. Keep it below 0.5.
  3. Enter the transformer secondary-to-primary turns ratio.
  4. Provide switching frequency in kilohertz.
  5. Enter the load resistance seen by the converter output.
  6. Supply realistic efficiency and diode drop values.
  7. Choose ripple current and ripple voltage targets.
  8. Press Calculate Converter to display results above the form.
  9. Use CSV or PDF export buttons to save the result table.

This tool is best for feasibility studies, educational checks, and quick component sizing. Use simulation and detailed loss analysis before hardware release.

Frequently Asked Questions

1. What does this calculator estimate?

It estimates output voltage, current, power, input current, switch stress, filter inductance, output capacitance, ripple behavior, and transformer apparent power for a half bridge converter.

2. Why must duty cycle stay below 0.5?

In a half bridge stage, each switch should conduct within its own interval. Keeping duty below 0.5 helps avoid overlap and supports realistic transformer reset assumptions.

3. Is the output voltage exact?

No. It is an engineering estimate. Real output depends on rectifier type, dead time, winding resistance, leakage inductance, control method, ESR, and thermal conditions.

4. What turns ratio should I enter?

Enter Ns/Np, meaning secondary turns divided by primary turns. A value below 1 reduces voltage, while a value above 1 steps voltage upward.

5. Why is effective ripple frequency doubled?

After full-wave rectification, the output filter often sees two energy transfer pulses per switching cycle. That doubles the ripple frequency used in basic sizing equations.

6. Can I use this for synchronous rectification?

Yes, but set diode drop near zero or replace it with the equivalent conduction drop expected from synchronous devices. Final loss modeling should still be checked separately.

7. Does this include magnetic core design?

No. It does not calculate flux density, core loss, copper loss, window fill, gap length, or thermal rise. Those must be verified in a separate magnetics design process.

8. When should I use simulation after this?

Use simulation whenever component stress, transient response, startup behavior, duty limits, transformer leakage, or feedback stability matters. This calculator is a first-pass design aid.