hello
I am building my own am3358 based board
and i have a question on the uart0 in the schematic of the BBB
why do we need a SN74LVC2G241?
why dont connect directly to the header?
why a pull down resistor if uart0_rx and uart0_tx has already a internal pull up resistor?
Thanks in advance.
When you have the FTDI cable plugged in and you power of the BBB, it tries to power the processor through those pins. The result is a blown processor. The 241 provide isolation. If you are careful and you never have the FTDI cable plugged in when you power off the board, you do not need it.
This is all described in the SRM.
Gerald
Sounds like “cheap insurance” to me . . .