Other Parts Discussed in Thread: TMUX1511, SN74CB3Q3245, TMUX1109, TMUX1112
In my design I use 4 UARTs (operating with 1V8 logic) for communications with different peripherals (like GPS, Bluetooth). If some peripheral is no needed then it is powered down and MCU RX/TX lines are set to high impedance. However, for debugging and testing purpose I have UARTs sniffer (with possibility to listen for data and to inject data) connected to these 4 UARTs (build based on FT4232). I've noticed that there is back-powering from FT4232 to disabled external peripherals. I wonder how to prevent this back-powering and one of my idea is to use switch like SN74LV4066A. However, because I don't know its internal structure I cannot be sure it will be working or not. Do you have any experience with SN74LV4066A and can advice if it is right solution? If SN74LV4066A is not the right choice then what is your recommendation?