Boost Converter Calculator

A boost converter is a DC-to-DC power converter that steps up voltage from its input to its output. It's a type of switched-mode power supply that uses energy storage elements (inductors and capacitors) along with switches to efficiently convert lower input voltages to higher output voltages.

The duty cycle (D) of a boost converter is calculated using the formula: D = 1 - (Vin / Vout). This represents the fraction of time the switch is ON during each switching cycle. For example, if Vin = 12V and Vout = 24V, then D = 1 - (12/24) = 0.5 or 50%.

Switching frequency affects component size, efficiency, and EMI. Higher frequencies allow smaller inductors and capacitors but increase switching losses. Typical frequencies range from 50kHz to 2MHz. Choose based on your size constraints, efficiency requirements, and EMI considerations.

A buck converter steps down voltage (Vout < Vin) while a boost converter steps up voltage (Vout > Vin). Buck converters have duty cycles less than 1 and are used for voltage reduction, while boost converters use the stored energy in inductors during switch-off periods to achieve voltage multiplication.

Inductor value affects ripple current and converter size. Use the formula: L = (Vin × D) / (ΔIL × fs), where ΔIL is the desired ripple current and fs is switching frequency. Smaller inductors have higher ripple current but are more compact. Typical ripple current is 20-40% of average inductor current.

Inductor ripple current is the AC component of current flowing through the boost inductor, representing the difference between peak and minimum current. It affects component stress, efficiency, and output ripple. Lower ripple current reduces component stress but requires larger inductors.

Maximum switch current equals the peak inductor current: Iswitch_max = IL_avg + ΔIL/2, where IL_avg is the average inductor current and ΔIL is the ripple current. This determines the current rating requirements for your switching device (MOSFET or transistor).