DS90UB941AS-Q1: coaxial cable and the STP cabl

Hi Customer,

STP cable has better noise immunity because the shielded twin pair helps reduce EMI through cable transmission due to its differential nature. It also has a higher voltage swing allowing for longer transmission distances.

Coax cable tends to have much lower loss per unit length when compared with STP which makes it desirable for longer cable distances. It also typically comes with cost advantage compared to STP. Since coax is single ended, it may have disadvantage when it comes to EMC emissions/immunity, but note that we have found in reality that with good quality coax cable such as Dacar 302, the EMC performance can be even better than with most common automotive STP cable types.

The main consideration to make when moving from STP to coax is to ensure that the datasheet pin connection recommendations are taken into account to terminate the interface properly, and to make sure to select good quality coaxial cable such as Dacar 302. Also some older devices such as DS90UB94x require specific MODE strapping to work in coax vs. STP mode so that also needs to be taken into account.

Please refer to this article for your understanding. (What you need to know about high-speed cables for FPD-Link III SerDes)

Best,

Josh

Thanks for the reply，This resolved my issue， I got it.