We finished the project and made a little PCB. At each ADC input we placed an extra protection circuit, consisting of a resistor and dual diode. The resistor is calculated to keep an additional error due to the leakage current of the diodes below ½ LSB. R5…R8 (0 Ω) are used to set the I2C address (10010xx). Only one of these four resistors should be placed!
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