Stats

  • Locked Locked
  • Replies 4
  • Subscribers 167
  • Views 13564
  • Members are here 0
More Content
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Creating Stubs for Terminating Resistors

EllieRye

I am designing a PCB for a BGA. For the BGA inputs, I'd like to use terminating resistors so that physically they are as below:

 

Input------------->BGAPin------>resistor


However, the auto routing tools (understandably) want to route it as:

 Input------------->Resistor----> BGA Pin

 

Is there a way to specify a t-connection on the BGA pin, or some way to enforce the way nets are interpreted physically?

 

Thanks,

Megan

  • redwire

     Look up net scheduling.  Or better yet, pin escape it the way you want and move on.

  • hadeti

     Creating stubs can lead to Signal Integrity Issue. I will suggest you pick up a signal integrity book. For example"Signal Integrity for PCB Designers" by Vikas Shukla or "Signal Integrity Simplified" by Eric Bogatin.

  • dschaefer

     Here's a sample of net scheduling within a Specctra .do file (Allegro Router):

    define (net D5
    (fromto U6-5 RN1-6 )
    (fromto RN1-6 U7-5)
    )

    Lots of other controls you can add ..

    Hth,
    Dave

  • EllieRye

    Thanks Dave, that was just what I needed.

     

    Megan

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.