AN 958: Board Design Guidelines

ID 683073
Date 6/26/2023
Document Table of Contents Determine the Delay

Use the following equations to determine the delay for a 300-ps rise-time signal traveling through a transmission line embedded in a dielectric with an electrical permittivity of εr.

For stripline configuration:

For microstrip configuration:

In FR-4, a transmission line with a stripline configuration induces approximately 180 ps per inch of delay on the signal. Therefore, the velocity of the signal through the transmission line becomes the inverse of the delay, which is 5.5*10-9 inches per second.