Altera Power Delivery Network - Manual (Page 17)

Chapter 1: Power Delivery Network (PDN) Tool User Guide 1–13
Setting Up the PDN Tool
© March 2009 Altera Corporation Power Delivery Network (PDN) Tool User Guide
Cap Mount Tab
The Cap Mount tab, shown in Figure 1–10 , is used to calculate the capacitor mounting
inductance seen by the decoupling capacitor.
The capacitor mounting calculation is based on the assumption that the decoupling
capacitor is a two-terminal device. The capacitor mounting calculation is applicable
for any two-terminal capacitor with the following footprints: 0201, 0402, 0603, 0805,
1206, and so on. Based on the layout, you can enter all the information and the tool
will provide a mounting inductance for a capacitor mounted on either the top or
bottom layer of the board. Depending on the layout, you can choose between Via on
End or Via on Side to acheive an accurate capacitor mounting inductance value.
If you plan to use a different footprint capacitor other than a regular two-terminal
capacitor or X2Y capacitor for decoupling , you can skip using the Cap Mount tab and
directly enter the capacitor parasitics and capacitor mounting inductance in the
Library
tab (under the Custom field in the Decoupling Cap section of the library). As
with the other tabs, you can save the changes made to the tab, restore the changes, and
restore the tab back to the default settings.
Figure 1–10. Cap Mount Tab