I want to make sure that on my development board, the guys can control loads through the logic level MOSFET or alternatively use the pin as a GPIO for serial data.
I have these issues and can't decide:

1. 1. If I use a buffer before the jumper, when the voltage is shifted, RDS(on) will also change, and I want the MOSFET to always work at a VGS voltage of 5V.
2. 2. If I use the buffer after (as shown in the attached circuit), the GPIO pin is not protected by the buffer and I cannot make the MOS work at 5V. Does anyone have any ideas on how to optimize the architecture topology?

Thank you in advance for your help.

 

cannot offer suggestions without knowing what the part numbers are...

 

@panic mode
Sorry,
MOSFET: ZXMS6006DGQ-13
Buffer: SN74LVC1T45DBV

 

that mosfet works with either 5V or 3.3V