We're using the LTC2271. The analog inputs, could occasionally have voltages as high as 10 V. Under absolute maximum ratings on page 2 the datasheet says the range is -0.3V to VDD+0.2V (2.0V). But then note 3 on page 6 says:
Note 3: When these pin voltages are taken below GND or above VDD, they
will be clamped by internal diodes. This product can handle input currents
of greater than 100mA below GND or above VDD without latchup.
This seems to imply we can let the voltage go to 10 V so long as we use say a 100 ohm resistor to limit the current. But then the purpose of the absolute maximum rating on the voltage is unclear.
Or do we need to add clamps on Ain to limit the voltage to VDD + 0.2 V?