We use AD9245 to sample the signal detect single end amplifier with output voltage from 0 to 2 volts. We connect this output to Vin+. My question is that should we connect the Vin- to ground or to a voltage reference of 1 volt. If we connect the Vin- to ground, the differential input of AD9245 will be from 0 to 2 volts. If we connect the Vin- to 1 volt reference, the differential input of AD9245 will be from -1 to 1 volt. Could you please tell us which solution is right or both are right?
For a 2 V input single-ended input span ranging from 0 to +2 V, the VREF output must be configured for 1 V while the VIN- pin is connected to VREF via the same value resistor (i.e. 33 ohms) that is used to connect VIN+ to the amplifier source which is producing the 0 to 2 V input signal.