Tool/software:
We have a circuit card designed many years ago that uses SN75452s to drive digital data signals down a cable through a transformer coupled interface. I've been asked to look into what the impact would be if the termination resistors at the receiving end became disconnected and it seems, if my analysis is correct, that it could result in reflections that would drive the open collector outputs of the IC to negative voltages. The questions I have are whether there is any protection on the outputs against going negative (i.e. clamping diodes?) and, if not, what the breakdown voltage might be where a negative voltage might cause damage?
