ADC MCP3208 differential mode exceeding the specs - will this the device damage?

StefanL38

Hello,

I took a look into the datasheet of the MCP3208.
For pseudo differential mode it says
Analog Inputs
pseudo-differential Mode

min-voltage on IN+ = IN-
max-voltage on IN+= VRef + IN-

min-voltage on IN- = VSS-100 mV
max-voltage on IN-= VSS+100 mV

As I don't want to fry several chips until I know it, my question is:
If the voltages exceed these specs. Does the chip give back only strange values or will it destroy the chip?

a) if it happens ONE time accidently ?
b) if it happens for hours and days or 10.000 times?

see also attached picture

best regards

Stefan

kwinn

Stefan, most likely you will fry the chip if you exceed the maximums. You might get away with it if it is only a few mV over the max since even the max ratings have a safety margin to allow for processing variations but I would not count on it.

StefanL38

Thank you kwinn for your information.

Aha. OK. I want to use this chip for voltage and current measurings. As the differential mode needs two channels anyway I can set up a software-differential mode by using two channels configured on the ADC-chip as
single-ended connected to the ends of the current-measuring shunt-resistor and calculate the voltage-difference in the software. So with this way I'll keep to voltages connected to the MCP3208 always above the specs
lowest (=GND) and inserting a voltage-follower between sunt-resistor and ADC. Then I could supply the voltage follower by a voltage so the output is clipping the voltage at VRef - 100mV to stay surely under VRef.

best regards

Stefan