Platform forum

Calculation of differential pair impedance

Mohammad , 06-13-2022, 05:50 AM
Hi guys
I am using the Saturn PCB toolkit for calculating differential pair impedance and there is a 6 to 10 ohm difference between Saturn and allegro calculations for the same stack-up and trace width and spacing. can anybody help me with this problem? Which one should I trust?
Also, which IPC standard does Allegro use for calculations? IPC-2152?
robertferanec , 06-13-2022, 07:41 AM
Only trust numbers from your PCB manufacturer. Everything else is just approximate.

PS: I have explained this many times. Only PCB manufacturer can give you exact numbers, because manufacturing controlled impedance tracks is not only about putting theoretical numbers into a calculator - these numbers will change during PCB manufacturing process e.g. final dielectric thickness may be different.
Mohammad , 06-13-2022, 07:59 AM
Thank you ❤️ I have learned from you a lot. Do you know what IPC standard Allegro uses for impedance calculations?
robertferanec , 06-14-2022, 01:17 AM
Thank you for watching the videos. No, I don't know how Cadence calculates the impedance.
Use our interactive Discord forum to reply or ask new questions.
Discord invite
Discord forum link (after invitation)

Didn't find what you were looking for?