Question
I am using the DC coupled configuration in which VINN is shorted to VREFOUT of
1.25V and the input voltage is applied to VINPX (Fig. 27). What is the voltage
range on VINPX and LSB value in millivolts?
Answer
The data sheet gives 1.64375Vp-p input voltage (measured differentially). This
means the absolute voltage input has to account for the 1.25V reference:
1.25+/-1.64375/2 V for Figure 27 configuration
As for the LSB value, the bottom transfer function of Figure 8 (single ended)
should be used because Vref*0.6575=1.64375/2. Then, the digital output is
function of Data Mode/Mixed Mode bits: 16 or 15 bits.