In a project I'm working on, I'm planning to use the SN75174 to send a signal through about 30m of twisted pair. This signal has a bitrate of around 1Mbps (it's a signal to drive WS2811 LEDs,) and will be unidirectional – I have a device at the start of the wire with the SN75174, and at the other end with a matching SN75175 to convert it back into a single ended signal to provide to the LED strip.

Currently, I plan to terminate just the remote end with the receiver with a 100Ω resistor (I'm using Cat5 cabling, which has an impedance of about 100Ω±15%) but I'm wondering whether I should terminate it in the same way at the transmitter as well.

I also run a CAN bus over another one of the twisted pairs and that's obviously terminated at both ends with split termination and a capacitor to ground, but I'm not sure whether I need to do that since my signal is only going a single direction, or whether split termination is necessary for the LED signal.

TL;DR: Would there be any negative side effects of terminating this unidirectional signal at the transmitter as well? Should I be using split termination with two resistors and a capacitor to ground, rather than just a single resistor between the differential pairs?

Thanks for any help.


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