How to Calculate Propagation Delay
Access a calculator because you can do some quick math to calculate propagation delay. Propagation delay equals the distance divided by propagation velocity. Don’t know how to calculate propagation velocity? First you need to know the dielectric constant of the laminate you are using. In PCB design, this is most commonly FR4, which has a dielectric constant of approximately 4. Now you divide the speed of light (11.80285 in/nSec or 299.792458 mm/ns) by the square root of 4. In other words, propagation velocity is one-half of the speed of light when you are using FR4.
Creating a circuit board can require a lot of calculations and precise placement of components. Just one signal error can compromise your entire design. Being able to run an array of circuit simulations can help you see if you’ve calculated propagation delay correctly. CircuitMaker is a free EDA tool for would-be PCB designers of varying skill sets. Using the technology at CircuitMaker, you can run simulations on your board that check for:
Bit error rate
Simultaneous Switching Noise
Want to learn more about CircuitMaker and what it can help you do? Head to CircuitMaker.com now.