Q
I am using the DC coupled configuration in which VINN is shorted to VREFOUT of1.25V and the input voltage is applied to VINPX (Fig. 27). What is the voltage
range on VINPX and LSB value in millivolts?
A
The data sheet gives 1.64375Vp-p input voltage (measured differentially). Thismeans 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.