7i80db supply

hi, I have seen on the data that the 7i80 has a maximum current absorption of 5 amps ..
in reality, however, the 7i80 with 2 7i40 1 7i37 and 5 differential encoders reaches a maximum of 1.2 amps with a program running.
can I use a good 5 volt 2.5 amp power supply?
and if it's a bad idea to connect the +5 volt also to the microstep drive logic of the A axis
Thanks in advance
Mauro