Forum Discussion
Ian_Maw
New Contributor
New ContributorDoes the PDN Tool Take DC Bias Loss Into Account?
Hi, I worked in a company where someone did not account for loss of capacitance due to DC bias and the boards were unreliable for that reason. I used the Cyclone V PDN tool to calculate the require...
- Accepted. Let's say, PDN tool has no features to take account of capacitor voltage rating. Even if you know it, effective capacitance of different high Er capacitors at 0.5*Vrated ranges between 30 and 80 % of nominal capacitance.
Farabi_Altera
Regular Contributor
Regular ContributorHello,
When designing a power circuitry for your Cyclone V fpga, In the EPE you need to use Power Characteristics to "Maximum" instead of Typical. In PDN, please make sure the Zeffective is below the Ztarget.
In PDN the dynamic current change can be set to >40% for VCC for defensive design to make sure the decoupling capacitors able to deliver enough power for FPGA during ramp up and user mode.
regards,
Farabi
