Altera Power Delivery Network - Manual (Page 7)

Chapter 1: Power Delivery Network (PDN) Tool User Guide 1–3
Setting Up the PDN Tool
© March 2009 Altera Corporation Power Delivery Network (PDN) Tool User Guide
The PDN tool is designed to provide an accurate estimate on the number and types of
capacitors required to design a robust PDN, regardless of where you are in the design
phase. The accuracy of the results is highly dependent on the user inputs for the
various parameters.
1 You can explore the tool by following the Quick Start instructions listed in the
Introduction
tab.
In the pre-layout phase of the design cycle, when no specific information about the
board stackup and board layout is known, you can follow the
“Pre-Layout
Instructions” on page 1–3 to explore the solution space when finalizing key design
parameters, such as stackup, plane size, capacitor count, capacitor orientation, and so
on.
If you have finalized the board stackup and have access to board database and layout
information, you can step through the various tabs and enter the required information
to arrive at a very accurate decoupling scheme.
Pre-Layout Instructions
In the pre-layout phase, you can ignore the Plane Cap, Cap Mount, X2Y Mount, and
BGA Via
tabs and go directly to the Library tab when you do not have layout
information. Figure 1–3 shows the fields located in the Library tab for entering the
various parameters.
If available, enter the values shown in Figure 1–3 in the Library tab. To use the default
values, go directly to the Decap Selection tab to begin the analysis.
Library This tab points to various libraries (capacitor, dielectric materials, and so on) that are called
by other tabs. You can change the default values listed as part of these libraries.
BGA Via This tab provides an interface to calculate the BGA mounting inductance based on
design-specific via parameters and the number of vias.
Plane Cap This tab provides an interface to calculate the plane capacitance based on design-specific
parameters.
Cap Mount This tab provides an interface to input design-specific parameters for calculating the
capacitor mounting inductance for two different capacitor orientations (Via on Side [VOS]
and Via on End [VOE]).
X2Y Mount This tab provides an interface to input design-specific parameters for calculating the
capacitor mounting inductance for X2Y type capacitors.
BOM The Bill of Materials (BOM) tab provides a summary of the final capacitor count required to
meet the target impedance.
Table 1–1. Description of Tabs in PDN Tool (Sheet 2 of 2)
Tab Description