You need to test, we're here to help.

You need to test, we're here to help.

16 August 2018

More on Quiet-Low I/O Drivers and Ground Bounce

To configure an I/O driver as a quiet-low line, its output is connected directly to Vss on the die
Figure 1: To configure an I/O driver as a quiet-low line, its
output is connected directly to Vss on the die
Ground bounce can plague digital I/O lines with bit errors and turn your hair grey trying to uncover the cause in the process. But there is a trick you can use to make the analysis a little easier: using a quiet-low I/O driver as a sense line to reveal the existence, and magnitude, of ground bounce in your system.

07 August 2018

About Ground Bounce and How to Measure It

Shown are five I/O drivers within a package driving signal lines on a PC board
Figure 1: Shown are five I/O drivers
within a package driving signal
lines on a PC board
Designing and/or troubleshooting a system with, say, an MCU driving signals across transmission lines, can be an interesting exercise in patience and diligent sleuthing. Perhaps you're seeing an inordinate amount of bit errors at the receive end of I/O lines but having some difficulty nailing down the source. In many cases, the problem is ground bounce, an issue that can be tough to diagnose and cure. Let's begin an examination of the ground-bounce phenomenon by explaining how it arises and then outlining an approach for finding it.