AN 958: Board Design Guidelines

ID 683073
Date 6/26/2023
Document Table of Contents Determining the fTARGET

The highest frequency of interest is the point in frequency after which adding a reasonable number of decoupling capacitors does not bring down the power rail impedance (ZEFF) below the target impedance (ZTARGET) due to the dominance of the parasitic planar spreading inductance and package mounting inductances. Typically, this fTARGET ranges from 50/60 MHz to 150/200 MHz. Beyond these frequencies, it is expected that power integrity is maintained and performed by the on-package and on-die capacitors of the selected target devices.