I have few questions about transforms operation. One of the main points of the transforms are ground isolation. Sorry if my question sounds so simple. let's say if have a transformer in the transmit unit. let's say that I want to transmit ethernet signals coming out ot ethernet chip. And let's say my internal circuit in the primary terminal runs at 5 volts.

First quesiton: What is going to be the voltage on the secondary terminals of the transformer?

Second question: Will we be also transmitting a ground reference to the receiving end? Or, it will just be a pair of differnetial signals?

Third question: Sorry if this one is very simple but do we always need a reference voltage when we send a differential signal? If not then how does the receive end knows the reference voltage?

I have few questions about transformer operation. One of the main points of the transformer is ground isolation.

Let's say if have a transformer in an ethernet transmitter, and my circuit in the primary of the transformer runs at 5 volts.

First quesiton: What is going to be the voltage on the secondary terminals of the transformer?

Second question: Will we be also transmitting a ground reference to the receiving end? Or will it will just be a differential signal?

Third question: Do we always need a reference voltage when we send a differential signal? If not, then how does the receiving end know the reference voltage?