AD2S80_arc min meaning

Document created by analog-archivist Employee on Feb 23, 2016
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I want to know the meaning of "Accuracy 8 arc min" in the datasheet of AD2S80A.
Does it means the error is 8 arc per minute?


The accuracy of an ADC is measured in terms of LSB.
The accuracy of an RDC is measured in terms of Arc Minutes. This is standard
for all resolver to digital converters.

There are 60 arc minutes in one degree. There are 21,600 arc minutes in one
full revolution i.e. 360 degrees x 60.

A 10-bit lsb = 21.1 arc min
A 12-bit lsb = 5.3 arc min
A 10-bit lsb = 1.3 arc min
A 10-bit lsb = 0.3 arc min

The spec on the AD2S80A datasheet is 8 arc min +1LSB. So at 10 bit resolution,
for example, this means that the max accuracy of the part is 29.1 arc min. If
the resolution is 16 bit the max accuracy is 8.3 arc min.