[PCB_FORUM] Re: NO_RAT property appearing from schematic

Andy!

 

Thanks! I appreciate the info!

 

Deac 
Work phone: (603) 886-8711 ext.202
Cell : (603) 557-7568



  

  _____  

From: icu-pcb-forum-bounce@xxxxxxxxxxxxx
[mailto:icu-pcb-forum-bounce@xxxxxxxxxxxxx] On Behalf Of Andrew Noonan
Sent: Thursday, April 28, 2005 12:15 PM
To: icu-pcb-forum@xxxxxxxxxxxxx
Subject: [PCB_FORUM] Re: NO_RAT property appearing from schematic

 

Hi Deac,

 

It definitely depends on the signaling edge rates coming down the pairs, and
to some extent, the data rate. The faster the edge rate, the further away
they should be.  For example, if the data rate is below 1Gbit/Sec,
diff-pairs on inner layers, with geometry of 5/5/5 (line-space-line), you
may be able to use a 15 mils air gap between pairs. But as the data rate
(and subsequently edge rate) increases, you will need to also increase the
space. It gets worse on outer layers, with air as part of the dielectric. 

 

So, the short answer is, no rules of thumb, it really depends on the
technology you're routing for. 

 

Andrew Noonan

Sr. PCB Designer

Topspin Communications

(w)650-316-3398

(c)650-814-3677

 

 

-----Original Message-----
From: icu-pcb-forum-bounce@xxxxxxxxxxxxx
[mailto:icu-pcb-forum-bounce@xxxxxxxxxxxxx] On Behalf Of Deac Descoteaux
Sent: Thursday, April 28, 2005 8:15 AM
To: icu-pcb-forum@xxxxxxxxxxxxx
Subject: [PCB_FORUM] Re: NO_RAT property appearing from schematic

Hi All!

 

Is there a rule of thumb for the distance from a diff pair to the next diff
pair? I heard that you should have twice the distance of the overall width
or the preceding diff pair.

 

Thanks

 

Deac 
Work phone: (603) 886-8711 ext.202
Cell : (603) 557-7568



  


  _____  


From: icu-pcb-forum-bounce@xxxxxxxxxxxxx
[mailto:icu-pcb-forum-bounce@xxxxxxxxxxxxx] On Behalf Of Gerry Meier
Sent: Thursday, April 28, 2005 11:07 AM
To: icu-pcb-forum@xxxxxxxxxxxxx
Subject: [PCB_FORUM] Re: NO_RAT property appearing from schematic

 

Was the property added in Allegro? 

 

 Gerry Meier
Sr. PCB Designer
Freedom CAD Services, Inc.
Voice: (603) 864-1300 x1350
Alt. Voice: (386) 753-0048
Email: gerry.meier@xxxxxxxxxxxxxx
visit our website at<http://www.freedomcad.com <http://www.freedomcad.com/> 

 

 


  _____  


From: icu-pcb-forum-bounce@xxxxxxxxxxxxx
[mailto:icu-pcb-forum-bounce@xxxxxxxxxxxxx] On Behalf Of Daniel So
Sent: Thursday, April 28, 2005 11:04 AM
To: icu-pcb-forum@xxxxxxxxxxxxx
Subject: [PCB_FORUM] NO_RAT property appearing from schematic

I am reading in a netlist from Concept which is suppose to have no
constraints or properties. However, I am getting a NO_RAT property on the
GND net. Doing a search on the ascii files of the schematic pages shows no
instances of this property. The property does not appear in any of the dat
files created from Concept. Any ideas where this property is coming from?

 

Thanks for any ideas

 

Daniel So

1065 La Avenida

Mtn View, Ca 94043

(650) 693-2054

email: danielso@xxxxxxxxxxxxx

Other related posts: