So I've found this document that explains the detailed circuit http://www.ti.com/lit/ug/tidua01/tidua01.pdf
As I mentioned before, I want to perform voltage sampling, in page 9 it mentions the following:
1.4 Potential Transformer and Voltage Transducer With 333-mV Output:
The design can also interface with a voltage transformer with rated voltages of 110 V or 230 V extending up to 600 V with output of 333 mV at a rated voltage.
Then on page 20 it mentions the following:
The AC input voltage applied is divided by a resistive potential divider. Multiple resistors are used to increase reliability and also withstand the surge input. The resistor divider is selected to have input impedance is >= 1 MΩ. The input voltage is divided by 1:990 ratio. The inputs are protected for ESD and Surge. The max input is 350 VRMS and the divider output is 350 mV. This is amplified by the non inverting amplifier with X17 gain. There are in total four amplifiers to measure the AC voltage.
The mains voltage is applied to the above voltage divider circuit. The capacitor is there to prevent input surges.
Please take a look and justify my answers. Thanks