On the Effects of Filter Capacitor Decoupling Capacitor and Bypass Capacitor(II)

The difference between bypass capacitor and decoupling capacitor.

Decoupling: removal of RF energy from high-frequency devices to distribution networks during device switching. Decoupling capacitors can also provide localized DC voltage sources for devices, which are particularly useful in reducing cross-plate surge currents.

Bypass: transfer of unwanted common-mode RF energy from a component or cable. This is mainly through the generation of AC bypass to eliminate inadvertent energy into the sensitive part, in addition to provide baseband filtering (bandwidth constraints).

We often see decoupling capacitors connected between the power supply and the ground, which have three functions: first, as the accumulator of this integrated circuit; and second, to filter out the high frequency noise generated by the device. The third is to prevent the noise carried by the power supply from interfering with the circuit.

In electronic circuits, decoupling capacitors and bypass capacitors play a role in anti-jamming. Capacitor in different positions, the address is different. For the same circuit, the bypass capacitor takes the high frequency noise in the input signal as the filter object, filters the high frequency clutter carried by the front stage, and the decoupling capacitor takes the interference of the output signal as the filter object.