The truth is that I am pretty new with Altium, so I really appreciate if you could help me in anything.
I am trying to make a PCB design with Ethernet connections. I have been looking the specifications for this type of connections and the main one is the impedance of 100 ohms.
For this I have created in my schematic differential pairs for my signals Tx + / Tx- and Rx + / Rx-.
I have also asked a supplier for the design- specifications, considering only two layers and typical characteristics of 35um copper and 1,6mm subtrate high.
I have recieved the following information:
= 5.1, Width W1
= 0.228mm W2
= 0.193mm, Space S
= 0.15mm (for impedance100.14 ohms).
W1 is the width without the lacquer layer and W2 the upper lacquer surface.
I start my design in Altium.
- Here begins my doubts, What width should I take for my design? W1? or an average between the two measures?
, I have created a rule in Clearance
for my differential pairs (InDifferentialPair ('DiffPairName')) where I have included a minimum of 0.15mm (if not I get an error every time I route the pairs).
I have also created another rule with these specifications Differential Pairs Routing (0.228mm Width; 0.15mm Gap) and I have included in Max Uncopled Length a value of 12.7mm,
- For Ethernet connections is this value correct or should it be considered a lower value ??
Finally in Matched Lengths
, I have activated "Within Differential Pair Length" with tolerance of 0.127mmThen, I have implemented my routing design.
In the routing, the truth is that I have been doing it taking care of the length instead of using the Interactive Length tuning tool.
I have run then, the Design Rule check without any error.
I have an average length in all sections of 42.5 mm (I have read that the maximum for Ethernet is about 75mm).
I attached the connection that I have made.
On the other hand, I have also tried to implemented with the xSignals tool, but I dont really appreciate many differences. I have created the different Xsignals with the wizard and I have been checking the different signals length in the PCB menu.
Do you think it could work? should i change anything??
I would appreciate any feedback and comment since I am totally beginner in this.
Thanks so much in advance