Controller area network voltages
There's no rocket science in CAN transeivers.

Normally, reference voltages are achieved using a simple voltage drop circuit or a linear volatage regulator.

Note, as there may be a large voltage drop between transmitter and receiver grounds (80&nbsp;V AFAIK) there's no need for precisely 2.5&nbsp;V. Low-voltage transceivers use a lower common-mode voltage.

So only a differential voltage of ±0.5&nbsp;V is actually regulated, and the common mode voltage can be set by a simple voltage divider.

There are some interesting schematics in the article Isolated CAN Transceiver Assures Robust Fieldbus Design.

Note the diodes feeding CAN-Low and CAN-High. Together with output transistors they give about a 1.5&nbsp;V drop. (They also protect the transistors from reverse current.)