The FTDI ft230X datasheet states that, for the output pin of the internal LDO:
When VCC is 3V3; pin 8 is an input pin and should be connected to pin 10.
Meaning that 3V3OUT of the internal LDO should be connected to the power supply (VCC) when the chip is being powered by 3.3V.
The datasheet also states that the maximum output of the LDO is 3.6V. page 17.
The 3V3OUT is internally connected to some modules(USB transceiver and reset generator). page 13.
I am assuming that since the LDO "may" output 3.6V, that the USB transceiver and reset generator will be fine if connect 3.6V to both the 3V3OUT and VCC pin.
Is this assumption correct?
This is for an application where an input voltage of both 3.3V and 3.6V are possible on VCC.
Ordinarily, when VCC is at 3.6V the LDO will be attempting to regulate down to 3.3V. BUT! since the LDO output is ALSO connected to VCC, there will be no current through the LDO. The LDO may attempt to lower it's output voltage by increasing it's pass element's resistance, but this will have no affect since the output is help at 3.6V.
Is this safe? Having the same voltage on both the input and output of the LDO, that is higher than what the LDO is trying to regulate down to?
(we know that VCCIO, USB transceiver and reset generator can handle 3.6V, so lets forget about that for now)