抑制△I噪声的去耦电容器应用技术

Techniques for Suppressing △I Noise by using Decoupling Capacitors

利用去耦电容器抑制△I噪声面临一些新的挑战.分析了去耦电容器的寄生参数对其高频性能的影响,总结了高速高密度PCB上去耦电容器的选择,并重点讨论了抑制△I噪声的去耦电容器应用技术.结果表明:利用去耦电容器抑制△I噪声,应多个去耦电容器并联使用,并恰当选择去耦电容器的种类、个数、电容值和自谐振频率,以得到期望的等效阻抗曲线.

Suppressing △I noise in digital circuits by using decoupling capacitors on PCBs is faced with some challenges. How the parasitic parameters of a decoupling capacitor affects its high frequency performance is analyzed, how to select decoupling capacitors outlined, and the use of the multiple decoupling capacitors for suppressing △I noise discussed in this paper. The results illustrate that using multiple decoupling capacitors and seletting properly the type, number, capacitance, and self-resonant frequency of the decoupling capacitors are essential to the expected equivalent impedance curve of dccoupling capacitors.