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By alex.sneedmiller
#195611
Hi Everyone,

I'm trying to figure out if there's a reason I would want to use a FTDI board that is 3.3V instead of 5 volts. My understanding is that the 5V or 3.3V is used to power the VCC output pin. Is that right?

The 5V FTDI breakout board has a max output current rating that is just limited by the USB port that it is powered from, and the 3.3V is limited to less than 50 mA. It makes sense to me that you could power a micro controller off of the 5V breakout board. Do people use the 3.3V FTDI breakout board to power 3.3V systems that run on less than 50mA?

Thanks,
Alex


5V FTDI: https://www.sparkfun.com/products/9716
3.3V FTDI: https://www.sparkfun.com/products/9873
Electrical Specs: https://learn.sparkfun.com/tutorials/sp ... 1499699570
By n1ist
#195703
That voltage also powers the I/O pins on the FTDI. A 5V FTDI will have its output pins swing to 5V, which can kill a 3.3v-only input...