AD8218 errors due to input offset voltage and ground rail saturation voltage

Document created by analog-archivist Employee on Feb 23, 2016
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Can you please confirm that errors due to input offset voltage and ground rail
saturation voltage, will be eliminated if we ground ENB pin according to page
11 in the datasheet?  How the offset is overcome?

 

Enabling the offset pin means the output starts at 80mV. This is over the
specified saturation range of our output, listed at 20mV in the datasheet. So,
if you had zero current and wanted 0V out, you can’t have it. But, by enabling
the offset, with 0A of load current the output starts at 80mV. If you just make
sure that the ADC knows this relationship, now you have an easy way of
measuring 0A of load current through the shunt resistor.

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