Propagation Delay Example
Propagation delay on a PCB can be calculated by dividing the distance of a wire from one pin to another by the propagation velocity. For example, working in millimeters, say you have a wire that is 8 mm. Now to calculate propagation velocity we are going to divide the speed of light (299.792458 mm/nSec) by the square root of the dielectric constant. Because many PCBs use FR4 as their dielectric material, we will use that in our example. The propagation velocity is, therefore, 149.896229. So 8 divided by 149.896229 equals 0.05337. That is the propagation delay of this particular signal.
Propagation delay has to be taken into account when designing your PCB because you need to make sure you maintain signal integrity throughout your design. A software, like Altium Designer, can help you verify your design by running simulations.
Altium Designer’s true integrated digital and analog simulator allows you to:
Create and manage several simulation profiles
Run the same simulation with alternate parameters and options
Add, edit, run, remove, and/or generate netlists
Altium Designer is the most widely used PCB design platform on the market because of all of its features and ease of use. Start a free trial today to learn more about how it can help you.