I am working with an FTDI "FT232R" IC [USB to UART conversion], and struggling to understand what the VIH spec of the IC is. I can only find reference to an 'Input switching threshold (VIN)' spec in the datasheet and that doesn't seem to change with VCCIO [IO voltage domain].
- What is the relation b/w the 'input switching threshold' spec and the traditional 'VIH' spec?
- Why wouldn't the VIN spec change with VCCIO?
- If the UART i/f on my MCU operates on 2.4V, does the VIN of 1.5V max mean that I might be OK if the VOH of the MCU is > (1.5V +VHys)?