Views:0 Author:Site Editor Publish Time: 2018-04-12 Origin:Site
Decoupling capacitor is a small battery to meet the current changes in the circuit to avoid the coupling interference between each other. The understanding of this can be referred to the calculation of the bulk capacitor of the power supply, which is similar to this. .
The bypass capacitor is actually de-coupled, but the bypass capacitor is generally referred to the high-frequency noise bypass, that is, to improve the high-frequency switching noise a low-impedance leakage way.
So the general bypass capacitor is much smaller than the decoupling capacitor. According to different load design conditions, the decoupling capacitor may be very different, when the bypass capacitor generally changes little. I personally disagree with the statement that "bypass is to filter the interference in the input signal, while the decoupling is to filter the interference from the output signal to prevent the interference signal from returning to the power supply." Because high-frequency signal interference can be coupled from input to output, decoupling can be a load surge output signal or a sudden change of input signal source, so I think how to distinguish is a bit worried.