Capacitance Role in PCB Board Schematic Reverse Engineering Design

As one of the passive components, the function of the capacitor is nothing more than the following in the progress of PCB Board Schematic Reverse Engineering Design:

Power circuit to realize the functions of bypass,

Energy storage.

First of all let’s talk about Bypass, the bypass capacitor is an energy storage device that provides energy for the local device. It can uni-formize the output of the regulator and reduce the load demand. Just like a small rechargeable battery, the bypass capacitor can be charged and discharged to the device.

In order to minimize the impedance, the bypass capacitor should be as close as possible to the power supply pin and ground pin of the load device. This can well prevent the ground potential rise and noise caused by the input value being too large. The ground bounce is the voltage drop at the ground connection when a large current glitch passes through it.

2nd important aspect of its functions is Energy storage

The energy storage capacitor collects the charge through the rectifier and transfers the stored energy to the output terminal of the power supply through the lead of the converter. Aluminum electrolytic capacitors with a voltage rating of 40-450VDC and a capacitance value of 220-150 000UF are more commonly used.

Depending on different power requirements, devices sometimes adopt series, parallel, or a combination of them. For power supplies with a power level of more than 10KW, larger tank-shaped screw terminal capacitors are usually used.