In IPC-D-275 on p. 13 there are formulas for Zo and Co for stripline and dual stripline PCB structures. Can anyone confirm for me that these formulas are (approximately) correct, or have there been any revisions to them? In particular, for the two Co formulas, if you plug in identical values for the variables (letting C = H in the dual stripline case) you get a higher value for Co in the dual stripline configuration than you do in the basic stripline one. This seems counterintuitive to me --- why would unit capacitance be HIGHER in the dual stripline configuration? Thanks for any help you can give Doug Brooks [log in to unmask] *************************************************************************** * 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] * ***************************************************************************