Stats

Locked Locked
Replies 2
Subscribers 163
Views 976
Members are here 0

2 SI Question,thanks

1 GND Vias beside high-speed signal via.
If there are more than one gnd layer, the GND via can should be used to provide a continuous signal returning current path, right? But if there is only one gnd layer, are the gnd vias still usefull?If useless, should the gnd vias be removed?

2 how to understand signal returning current on a Plane underneath that is not a GND layer?
ex: a VCC plane layer stacked closely under a signal layer, how to understand the returning current on VCC layer?

Originally posted in cdnusers.org by tfsummer

archive over 18 years ago

Yes, you can use GND vias for a signal return path. If you have only one ground layer, hopefully you can route the signal from one side of that layer to the other. Return current will also travel on VCC planes. If your signal transistions from using a GND layer to a VCC layer it helps if the two power layers are tightly coupled with as thin a dielectric as possible. Nearby decoupling capacitors also help shunt high-speed return currents between two planes, as long as their mounting inductance is minimized.

Originally posted in cdnusers.org by Donald Telian
Cancel
Vote Up 0 Vote Down

Cancel
archive over 18 years ago

Donal Telian,

Thank you very much for your help!

Originally posted in cdnusers.org by tfsummer
Cancel
Vote Up 0 Vote Down

Cancel

Cadence Guidelines

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.