Capacitor Impedance in a PDN: Derivation

What mathematics influence a PDN impedance spectrum's shape? Tech Consultant Zach Peterson explores which circuit parameters dominate the shape of the PDN impedance spectrum, as well as derivation in this power integrity video.
0:00 Intro
0:39 Where the Shape Comes From
3:41 Equivalent Circuits
5:22 Capacitor Impedance
8:28 Critical Points
For more Power Integrity videos, click here: • Power Integrity
For more PCB Design for Intermediate Users videos, click here: • PCB Design for Interme...
For more Tech Consultant Zach Peterson videos, click here: • Technical Consultant Z...
👉 Ebook: PDN Simulation and Analysis Guide: resources.altium.com/p/pdn-si...
👉 Power Delivery Network Simulation Deep Dive - Part One: • Power Delivery Network...
👉 Controlled ESR Capacitors: • Controlled ESR Capacitors
👉 15 Days Free Altium Designer Access: altium.com/yt/altium-academy
Don't forget to follow us on social to stay up-to-date on the latest Altium Academy content.
👉 Follow Altium on Twitter: / altium
👉 Follow Altium on Linkedin: / altium
👉 Follow Altium on Facebook: / altiumofficial
👉 Ready to try the industry's best-in-class design experience yourself? Download it today and get started! www.altium.com/downloads?utm_...
The Altium Academy is an online experience created to bring modern education to PCB Designers and Engineers all across the world. Here you can access a vast library of free training and educational content covering everything from basic design to advanced principles and step-by-step walkthroughs. Join industry legends as they share their career knowledge, review real-life design projects, or learn how to leverage one of Altium's leading design tools. No matter your level of experience, the Altium Academy can help you become a better Designer and Engineer!
About Altium LLC
Altium LLC (ASX:ALU), a global software company based in San Diego, California, is accelerating the pace of innovation through electronics. From individual inventors to multinational corporations, more PCB designers and engineers choose Altium software to design and realize electronics-based products.
#Altium #pcb #electronics

[@mostafanfs]

Hey Zach!

[@mohannadasar6126]

Hi Zach, I remember in "Controlled ESR Capacitors" video that increasing ESR of Capacitor of fres=f1 flattens the curve between Z at fres and the peak point, same for the other capacitor, meaning increasing ESR of both capacitors can give a flat response which reduces the supply voltage oscillation in the time domain. I have a question here, doesn't it make no sense to increase ESR of a capacitor for better performance? or since you're talking about "off-chip" capacitors then it's different, meaning, on-chip capacitors implemented in each block in the SoC could require minimum ESR for other reasons? and off-chip could require high ESR for the flat response? could you explain the difference between the two types of capacitors? off-chip capacitors and on-chip for each SoC block modeled as Cdie & ESR?

[@Zachariah-Peterson]

In that question it was about using a controlled ESR capacitor in a PDN, but that is not really their intended usage. Technically you could use them, but you are correct that it does not make sense to increase resistance if you want to get to a lower PDN impedance. If you used controlled ESR capacitors with higher ESR value to get to a lower PDN impedance then you might need to use a lot of those controlled ESR capacitors in parallel to get the total PDN impedance below target.
In terms of on-chip, I will admit I have not looked into the controlled ESR aspect of those chip capacitors because I do not do IC design. I will say that those chips have higher capacitance density AND higher ESR so I think the response at high frequencies would naturally be flatter but I would have to look at data to be sure. There will also be differences between the different types of SoC capacitors (MIM, MOS, MOM, etc.)

[@cvillafane4694]

Hi Zach, in 5:54 equation there is no C.

[@Zachariah-Peterson]

That's because it's lumped into the natural frequency (omega-0).