Relation between PGA module reference setting and PGA output

Answer:

 

Question:Does the reference setting of PGA module affect the output of PGA?

Response:Yes.The output of PGA depends on the reference setting of PGA module.In general the output of PGA is given by the following formula.

                                     VO = (VIN - VRef).Gain + VRef


For example if the input to PGA is 2V , gain of PGA is 2,and Ref Mux setting in global resources window is Vdd/2 
± Vdd/2 then,the output of PGA module for different reference input is given below.

If the reference input to PGA module is VSS then the output of PGA will be 4V.
If the reference input to PGA module is AGND then the output of PGA will be 1.5V.