Altera Device-Specific Power Delivery Network - Manual (Page 21)

• 0201
• 0402
• 0603
• 0805
• 1206
You also have the option to either modify the default values or enter your own commonly used custom
values in the Custom field. If you are using a capacitor with a footprint that is not available in the tool,
you must use the Custom field to enter the capacitor parasitics and the corresponding mounting
inductance.
The decoupling capacitors section also provides the option for the user defined capacitors (such as
User1,...,User4). You can define the ESR and ESL parasitics for the various footprints and enter the
corresponding capacitor value in the System_Decap tab. Choose the corresponding footprint when
defining the capacitor values.
Bulk Capacitors
The bulk capacitors section contains the commonly used capacitor values for decoupling the power
supply at mid and low frequencies. You can change the default values to reflect the parameters specific to
the design.
X2Y Decoupling Capacitors
The X2Y decoupling capacitors section contains the default ESR and ESL values for the various X2Y
capacitors in the 0603, 0805, 1206, and 1210 footprints. You also can replace the default ESR and ESL
values with your own commonly used custom values.
BGA Via and Plane Capacitance
This section allows you to directly enter the values for effective via loop inductance under the BGA and
plane capacitance during the pre-layout phase when no design-specific information is available.
If you have access to design-specific information, you can ignore this section and enter the design-specific
information in the Plane Cap and BGA Via tabs that calculate the plane capacitance and the BGA via
parasitics, respectively.
VRM Library
The VRM section lists the default values for both the linear and switcher regulators. In the Custom field,
you can change the VRM parasitics listed under the linear/switcher rows or add the custom parasitics for
the VRM relevant to the design.
Spreading R, L Parasitics
This library provides various options for the default effective spreading inductance values that the
decoupling capacitors see with respect to the FPGA. These values are based on the quality of the PDN
UG-01157
2015.03.06
Bulk Capacitors 21
Device-Specific Power Delivery Network (PDN) Tool 2.0 User Guide Altera Corporation
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