Hi,
The C14 and C15 you have pointed out are input AC-coupling capacitors.
When the signal is connected to the INxP/M in AC-coupled mode, the device provides a DC bias voltage on the INxP/M pins in order to ensure that the voltage on these pins do not go below 0V due to AC-signal swings. The capacitors ensure:
a) This DC bias is blocked from reaching the input signal source.
b) Any unwanted DC voltages/offsets from the signal source don't reach the INxP/M pins.
As mentioned in the datasheet, the inputs can also be connected to the INxP/M pins in DC-coupled configuration, in which case the C14 and C15 capacitors are not needed.
However, even in DC-coupled configuration, the voltage on the INxP/M pins with AC-signal swings should be maintained within the recommended operation voltage at any instance, in which case the signal source must include a DC bias in order to ensure this.
Thanks and regards,
Lakshmi Narasimhan
