I am routing Ethernet traces from a Colibri iMX6ULL
computer-on-module to RJ45 Ethernet connector (In-build Transformer). The layout design guide says that Ethernet should have 95 ohm differential and 50 ohm single-ended impedance.
I have following connecions:
- Ethernet TX+
- Ethernet TX-
- Ethernet RX+
- Ethernet RX-
- Ground
I am confused how to achieve a particular single-ended impedance and differential impedance at the same time for Ethernet. My PCB fabricator has shared an impedance sheet with me which lists trace width and spacing to achieve particular impedance.
They have mentioned 7.5 mil trace width for differential impedance of 95 ohm and 9.18 mil trace width for Single-ended impedance of 50 ohm. I need to maintain differential impedance of 95 ohm and single ended impedance of 50 ohm for Ethernet connections as specified in the above layout design guide (Page 34). How can I select an appropriate trace width and spacing for Ethernet connections?