Design a boost (step-up) DC-DC converter: calculate duty cycle, inductor current, ripple, critical inductance, and component stress for any input/output voltage.
The **Boost Converter Calculator** designs and analyses a step-up (boost) DC-DC converter — the workhorse topology for increasing voltage in solar MPPT chargers, LED drivers, battery-powered electronics, and industrial power supplies. Enter the input voltage, desired output voltage, load current, switching frequency, and inductor value, and the calculator returns the duty cycle, input/inductor current, current ripple, CCM/DCM boundary, component stress, and power loss estimates.
Understanding the duty cycle-voltage relationship, ripple magnitude, and continuous versus discontinuous conduction modes is critical for reliable converter design. The built-in presets cover common applications: 12 V to 48 V solar, 5 V to 12 V USB-PD, 3.3 V to 5 V logic, and 24 V to 170 V LED driver. The reference tables make it easier to see when a design choice reduces ripple at the cost of higher current stress or switching loss. That makes it easier to compare a few operating points quickly and see which one best fits the current and thermal limits you have available. It also helps when a candidate design needs to be checked against a different load or switching frequency before you commit to the magnetic parts.
Boost-converter design is a tradeoff between voltage gain, efficiency, ripple, and component stress, and those tradeoffs move quickly when the duty cycle gets high. This calculator lets you check the main equations together so you can iterate on inductance, switching frequency, and load current without losing track of current ripple or peak stress.
Duty Cycle: D = 1 − Vin/Vout Input Current: Iin = Iout / (1 − D) Inductor Ripple: ΔI = Vin × D / (L × f) Critical Inductance: Lcrit = Vin × D(1−D)² / (2 f Iout) Switch/Diode Stress: Vout (voltage), Ipeak = Iin + ΔI/2 (current)
Result: D = 75%, Iin = 8 A, ΔI = 4.09 A (CCM)
Boosting 12 V to 48 V at 2 A output requires 75% duty cycle and draws 8 A average from the source. With a 220 µH inductor at 100 kHz, ripple is ~4 A (51%) — CCM is maintained.
The ideal duty-cycle equation is simple, but the design gets harder as the target output rises further above the input. High duty cycle increases switch current, raises ripple sensitivity, and leaves less timing margin for real controllers. If the result lands near the practical limit of your controller, it is usually worth comparing multiple stages or a different topology instead of forcing one aggressive boost stage.
Average current alone does not tell you whether the design is comfortable. Inductor ripple determines peak current, conduction mode, and control behavior at light load. Use the calculator to check whether the converter stays in CCM where you need it, and whether the ripple percentage is reasonable for the magnetic size and thermal budget you have available.
Voltage gain is only one design target. The switch, diode, and inductor must all survive the real peak current and output-voltage stress with margin. After using the calculator, compare the predicted peaks against datasheet limits and then validate efficiency and temperature rise in hardware.
A boost converter is a switching topology that outputs a voltage higher than the input by storing energy in an inductor during the on-time and releasing it through a diode or synchronous switch during the off-time. It is one of the standard DC-DC options when a source must feed a higher-voltage load from the same supply rail.
The fraction of each switching period that the MOSFET is on. Higher D means higher output voltage, but it also increases current stress and ripple sensitivity.
Continuous Conduction Mode (CCM): inductor current never reaches zero. Discontinuous (DCM): it does. CCM is easier to control and more efficient at high loads.
A boost converter is a voltage-up, current-down converter. Power (V × I) is roughly conserved, so higher output voltage means lower output current but higher input current.
Parasitic resistances, diode drop, switch losses, and controller duty-cycle limits all reduce practical performance. Even if the ideal equation suggests a very large step-up, efficiency and peak current often become unacceptable first.
Cout ≥ Iout × D / (f × ΔVout). Larger capacitance and higher frequency reduce output ripple.