About xSignals
mulfycrowh , 02-10-2021, 12:35 PM
Hi everyone,
I would like to route as differential the paths TX_N, TX_P, RX_N and RX_P as shown on the attached screenshot.
U14 could be defined as the source, the connector (P2) as the destination.
As you can state, there are 4 series resistors.
I went to Design > xSignals > Create xSignals.
How should I proceed?
I tried many things.
Could you help please?
I would like to route as differential the paths TX_N, TX_P, RX_N and RX_P as shown on the attached screenshot.
U14 could be defined as the source, the connector (P2) as the destination.
As you can state, there are 4 series resistors.
I went to Design > xSignals > Create xSignals.
How should I proceed?
I tried many things.
Could you help please?
mulfycrowh , 02-10-2021, 01:10 PM
If I select P2 as source and R48, R50, R52, R54 as destinations in the wizard, AD detects all 4 differential signals.
But if I select P2 and U14, AD detects nothing.
But if I select P2 and U14, AD detects nothing.
goncaloc , 02-11-2021, 03:18 AM
The signals coming from U14 are not defined as differential signals, they should, as it is done on both TX and RX, end with _P and _N
robertferanec , 02-15-2021, 12:53 AM
@goncaloc nice spot! @mulfycrowh is it working after naming the nets correctly?
mulfycrowh , 02-16-2021, 02:22 PM
@robertferanec I thought that AD could automatically detect the series resistor within the differential pair. It is doable!
mulfycrowh , 02-16-2021, 02:23 PM
If I introduce another differential pair net, it is OK.
mulfycrowh , 02-16-2021, 02:30 PM
Now. I found that the suggested differential routing is not good as shown on the attached screenshot.
It is like like an automated routing.
Is there a way to go, in that case from the connector to the diode directly?
It is like like an automated routing.
Is there a way to go, in that case from the connector to the diode directly?
przemek , 02-17-2021, 02:07 AM
Hi,
you can adjust your traces after routing by sliding them. By the way, maybe rotate D9 by 180° to keep the nets close each other for as long as possible?
you can adjust your traces after routing by sliding them. By the way, maybe rotate D9 by 180° to keep the nets close each other for as long as possible?
mulfycrowh , 02-17-2021, 04:10 PM
Here is the result of my differential routing.
It is very hard to keep the impedance on each point because of the size of the components.
It is very hard to keep the impedance on each point because of the size of the components.
Comments:
goncaloc, 02-18-2021, 01:44 AM
Looking good
mulfycrowh , 02-18-2021, 06:13 AM
@goncaloc What is the short key to disable snapping when routing differential pairs?
Thanks.
Thanks.
przemek , 02-18-2021, 07:31 AM
It should be Shift + E - switching between snaping to all layers/current layer/snapping off.
robertferanec , 02-18-2021, 10:52 AM
When routing, hold down CTRL
Use our interactive Discord forum to reply or ask new questions.