1. In AD input signal circuit design, it is proposed to series connected an appropriate resistor (20 to 200 Ohm) first, and then to the AD input port, while also parallel connect an bypass capacitance(0.1uF or more) to AD input port. (See below)

2. In PCB layout, the resistors and capacitors should be as close to the IC pins as possible in order to achieve the best protection. (See below)