Series resistor or flat clamping for Analog input protection
To protect against careless inputs (as clarified), my recommendation is a combination of series resistance with a shunt TVS diode. Make sure to size the TVS voltage for something greater than your signal (but sufficiently less than IC's max input) and then size the resistor so that it doesn't interfere with the signal being measured but is large enough to handle the current at Vcareless - Vtvs. Also, if you are sampling high-frequency (MHz range and up) signals look for low-capacitance TVS devices.







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