In the following section we will try to evaluate the formula for calculating filter capacitor in power supply circuits for ensuring minimum ripple at the output (depending on the connected load current spec). C = I / (2 x f x Vpp) where I = load current f = input frequency of AC
Theoretically, the larger the filter capacitor used for the power supply, the better. Generally, large capacitors filter low frequency waves, and small capacitors filter high frequency waves. The large capacitor is used to stabilize the output, and the voltage across the capacitor cannot change suddenly, so the output can be smooth.
In fact, the filter capacitor should also contain two aspects, which are also the large capacitance value and small capacitance value mentioned by you, which are used for decoupling and bypass. Theoretically, the larger the filter capacitor used for the power supply, the better.
A filter capacitor is a capacitor which filters out a certain frequency or range of frequencies from a circuit. Usually capacitors filter out very low frequency signals. These are signals that are very close to 0Hz in frequency value. These are also referred to as DC signals. How filter capacitors work is based on the principle of .
For a voltage with as little residual ripple as possible, the capacitor must be the right size. However, it may not be infinitely large, as the diodes could be damaged. We want to explain how a smoothing capacitor can be dimensioned and how exactly it works. Our online filter capacitor calculator helps with dimensioning the capacity.
If the main operating frequency on your PCB is relatively low, it is also possible to add a few capacitors appropriately, one to filter out ripples and one to filter out high-frequency signals. If there is a relatively large instantaneous current, it is recommended to add a relatively large tantalum capacitor.