RockpiS Mic wiring

Just got round to wiring my mic modules to the RockPiS and reading through is the max input on the ADC 1.8v?

Confused as the mic bias is 3.3v and just thought this would be a matter of wiring vcc3.3 to my module and gnd and on the adc wire micp to my output and micn to gnd.

But now sort of confused after reading that max ADC voltage is 1.8v?
Where do I get 1.8v from?


Or should I ask with using Mic1-4 can I use a 3.3v mic module with a 2v swing with MicP to ouput and MicN to Gnd?