I have a USB to TTL Adapter. The Adapter uses the CP2102. I noticed that the CP2102 seems to derive it's power from the USB V+. My problem is that I need to supply power to the USB. The reason is that I need to drive a NULL USB cable. The transceivers (FT232R) requires 5V. I connected both the 3.3 and 5V and measured the Voltage at the USB and it is 3.3V. My plan is to just jumper the 5V to the USB V+. I don't have a schematic for the USB-TTL adapter. I believe This should work.
FT232R Datasheet: https://www.ftdichip.com/Support/Documents/DataSheets/ICs/DS_FT232R.pdf