Input Capacitor for a Boost Converter RMS current (ripple current) through the input capacitor: With the help of the REDEXPERT tool, a capacitor can now be selected with the lowest possible impedance at the switching frequency of 500 kHz, which at the same time meets the requirements in terms of ripple current as well as voltage.
This offers a stable capacitance of 22 µF in a very small package (5.3 · 5.3 · 5.8 mm³), a 16.3 mΩ ESR at 500 kHz and is specified for a ripple current of up to 2.2 A. Design of the input and output filters for a boost converter
The simplest way to calculate the input current of a boost regulator is to use the power balance equation, shown in Equation 1. For a DC/DC converter, the input and output powers are just the product of their respective currents and voltages. Adding the triangular ripple current, we arrive at Equation 2. ̧ ̧
Boost Converter Power Stage Integrated Circuit used to build the boost converter. This is necessary, because some parameters for the calculations have to be taken out of the data sheet. If these parameters are known the calculation of the power stage can take place.
The boost converter might still be able to output the desired current at that low input voltage because is the minimum switching current it can handle. But better to be safe than sorry. Here you can see the inductor will see a max of 0.94A at its lowest input voltage. Now we can chose the inductor for our design.
The boost converter is used to "step-up" an input voltage to some higher level, required by a load. This unique capability is achieved by storing energy in an inductor and releasing it to the load at a higher voltage. This brief note highlights some of the more common pitfalls when using boost regulators.