Expert Advice

Impedance: The Most Confusing Term in Signal Integrity

eric@beTheSignal.com — Mon, 09 Jul 2018 00:00:00 -0400

In more than 30 years of teaching signal integrity, I find the most confusing topic for engineers, even those working in the field for years, is the question of what is the impedance of a transmission line? Read on to learn about the 5 types of impedance.

Practical Modeling of High-speed Channels Based on Data Sheet Input

lsimonovich@lamsimenterprises.com — Mon, 02 Oct 2017 00:00:00 -0400

As Dave Dunham from Molex Corp. likes to say, "When designing high-speed serial links beyond 10 GB/s, everything matters." In order to ensure first time success at these speeds, accurate channel modeling is a prerequisite. This is especially true for long backplane channels.

The Perils of Right-angle Turns at DC

istvan.novak@verizon.net — Fri, 01 Sep 2017 10:00:00 -0400

Microwave engineers know that sharp corners and right-angle bends have their drawback at high frequencies. So what happens if we go to the other extreme of the spectrum, to DC? Istvan Novak takes a closer look.

How Much Capacitance Do We Really Get?

istvan.novak@verizon.net — Wed, 14 Jun 2017 00:00:00 -0400

We have to use enough capacitors so that the PDN functions properly. At the same time, to keep cost and size in check, we want to avoid overdesign and not use capacitors unnecessarily. Read on for advice on how to find the balance.

How Much Capacitance Do We Really get?

istvan.novak@verizon.net — Mon, 12 Jun 2017 13:52:00 -0400

Book Review: Principles of Power Integrity for PDN Design—Simplified

lsimonovich@lamsimenterprises.com — Tue, 23 May 2017 16:25:00 -0400

If you are looking for a good book to help you understand PDN design, then this book is a good place to start. Here's a synopsis of what you can learn in this mammoth volume.

What Exactly is Power Integrity?

eric@beTheSignal.com — Thu, 18 May 2017 09:00:00 -0400

Larry Smith and I address this question in the preface to our new book. We found this question to be a little like the story of the five blind people and the elephant. They each are asked, what is an elephant? Depending on what part they were facing, imagined the elephant as that feature: a wall, a rope, a tree trunk, etc.

Via Stubs – Are They all Bad?

lsimonovich@lamsimenterprises.com — Fri, 10 Mar 2017 00:00:00 -0500

We worry about via stubs in high-speed designs because they cause unwanted resonant frequency nulls which appear in the insertion loss plot (IL) of the channel. But are all via stubs bad? Well, as with most answers relating to signal integrity, “It depends.”

The Evergreen Question about PDN: Charge Delivery Time or Impedance

istvan.novak@verizon.net — Thu, 09 Mar 2017 13:25:00 -0500

Here's how to find a balance between delivering and supplying enough charge to the load in a timely fashion versus achieving a required impedance target

Useful SI/PI Tools from Istvan Novak

istvan.novak@verizon.net — Sun, 18 Sep 2016 08:58:00 -0400

Use SI/PI tools from Istvan Novak

Useful SI Tools from Eric Bogatin

eric@beTheSignal.com — Sun, 18 Sep 2016 08:39:00 -0400

Eric Bogatin's favorite SI tools

Useful EMC Tools from Doug Smith

doug@emcesd.com — Sun, 18 Sep 2016 08:20:16 -0400

Useful EMC tools and calculators from Doug Smith

Useful Tools SI/PI from Bert Simonovich

Sun, 18 Sep 2016 08:10:00 -0400

Here is my top 5 list and comments in no particular order of preference. Each tool has their strengths and weaknesses, but together they provide a good collection of tools for the SI/PI practitioner's tool box.