Analog Input on PIC16F88

[penelopepug]

Hi! The documention for the PIC16F88 says that the maximum input voltage to an input is VDD +0.3 volts I beleive. I have a circuit where a condition can occur such that there could be 100VDC through a 10k resistor to one of the analog inputs. Will this damage the input? I know that some people have detected zero crossing using a resistor connected directly to the mains but I think they used a very high resistance resistor. The only other specification I can see related to the analog inputs is the +/- 500nA leakage current. I would appreciate any help. Thanks.

[mackrackit]

I have a circuit where a condition can occur such that there could be 100VDC through a 10k resistor to one of the analog inputs.

What will the "normal" voltage be? If the 100 V is just a once and awhile possibility, a voltage clamp might do the trick. Other wise a resistor network will be needed.

And yes, 100 volt will smoke the PIC.

[tenaja]

In my experience, exceeding the rated voltage does in fact render the a/d converter incapacitated. btdt.