Electronic – use an ethernet jack to send LVDS signals

ethernetlvdsmagnetics

I would like to use an Ethernet jack for the form factor and CAT5e+ cable properties (shielded/twisted, characteristic impedance, etc) to send LVDS signals over a long length of cable (100+ ft). When choosing board Ethernet connectors, I see that there are all sorts of types out there. I am going to use the RJ45 T-568B wiring scheme, but then there are choices between magnetics, and I assume, no magnetics. Can I take advantage of the magnetically isolated jacks with an LVDS signal (coming from SN65LVDS31 driver), or will it likely interfere? My speeds will be in the 25 Mbps range. If the magnetic jacks will interfere, are there standard pin to wire type RJ45 connectors (no magnetics)?

Best Answer

LVDS signals are generally incompatible with transformers/magnetics. The Texas Instruments application note does not have any examples of this sort.

Here is a similar discussion, see this Xilinx thread.

The LVDS will likely work over 100ft of RJ45/CATwhatever connection, you just need no magnetics and correct termination scheme on driver and receiver sides. However, hot plug/reconnect could be problematic due to possibility of cable charge up and ESD killing your driver/receivers.

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