PCB Routing Bypass Capacitor and Capacitor Placement in PCB Design
PCB routing bypass capacitor involves adding capacitors near circuit routing in PCB design to reduce noise, enhance signal integrity, and improve stability. In high-frequency circuit design, bypass capacitance is a common technique for mitigating noise interference and improving signal quality.
Capacitor Functionality in PCB Design
A capacitor, composed of two conductors separated by a non-conductive insulating medium, stores charge when a voltage is applied. Capacitors connected in parallel with a load in a circuit help stabilize the working voltage by resisting voltage changes due to current fluctuations. By incorporating capacitors, resistors, and inductors in signal transmission circuits, various filters can be created to purify the signal.
How to Place Capacitors in PCB Design
Capacitors play a vital role in high-speed PCB design, categorized into filtering capacitors, decoupling capacitors, and energy storage capacitors.
- Power Output Capacitor, Filtering Capacitor: Filtering capacitors in power modules stabilize input and output power supply. The general principle is to place larger filter capacitors before smaller ones to meet current capacity requirements.
- Decoupling Capacitors: High-speed ICs require ample decoupling capacitors placed close to power pins for effective decoupling. Consider lead shortness, via and pad connections, and minimizing the decoupling loop.
- Energy Storage Capacitor: These capacitors deliver electrical energy quickly when needed. Focus on lead shortness, via density, and optimal via design for improved electrical performance.
Capacitors are essential in high-speed circuits for bypassing, decoupling, filtering, and energy storage, contributing to various applications like oscillation, synchronization, and timing.
