Other Parts Discussed in Thread: TMUX7462F, TMUX7308F
I have a design with 24 TMUX6208 multiplexers on the same 28V power rail. some of them sharing the output connections on the connector and the purpose is to route different input signals to the connector pins. The problem we have is while the board is powered down, if we apply voltage on S pin(connected to the connector) of the mux, the board works via the voltage on that pin. There is a reverse current flowing from this pin to VDD and to the 28V power rail which powers the board. What would be the reason and solution for this situation? Creating a power rail for all mux VDD pins and powering this from 28V through a diode would help?
Please share your suggestions and possible root cause of the issue.