Hi,
I am designing a board using a 3V3 supply normally provided by a TPS63001. But when programming the MCU on the board, the debugger will supply the power to the 3V3 rail of the board. Since the maximum input voltage on the Vout pin is 7V, I assume this means it handles backfeed current from another power source providing 3V3 on the Vout pin. Am I correct? If so, what will happen if the TPS63001 is under its normal operating mode (providing power) and we connect the debugger, providing 3V3 on the Vout net as well? Are there risks?
What do you think is the best way to handle this? I've heard of OR'ing power supplies with diode or special ICs, but do you think it is necessary? I do not care about sharing the load as both the debugger and the TPS63001 will be able to power the board on their own, but I want to design a system that will survive if:
TPS63001 provides power and the debugger is not connected
TPS63001 provides power and the debugger IS connected
TPS63001 does NOT provide power and the debugger IS connected
Thank you