Doug Brooks wrote: > > Various sources (e.g. IPC) have formulas for propagation > delay for microstrip and stripline configurations. Does > anyone know of a formula for propagation time in a > DUAL stripline configuration? Or is the stripline > configuration close enough? Hi Doug, I have calculated prop delay in a round about manner. I'll reference you to a Motorola ECL Design Apps book they published a while ago. In it prop delay is given as pd = (L*C)^0.5 L = inductance of the trace/inch (or whatever) C = capacitance of the trace/inch ( " ) I use *any* calculation I can get my hands on to get the C. L is a function of the trace itself. Typically about 20 nH/inch. I then drop these values into pd = (L*C)^0.5 for a prop/inch number, then simply multiply by the length of the trace for total delay. If this all sounds like flying by the seat of my pants, I agree. But, I would challange anyone to give me a reasonably accurate measure of trace inductance to 3 decimal places. I could be well wrong, so I would appreciate any ideas. Regards, Doug ************************************************************ ------------------------------------------------------------ The comments and opinions stated herein are mine alone, and do not reflect those of my employer. ------------------------------------------------------------ ************************************************************ *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************