Question
Data Sheet AD7621_pre.
In Table 2. Parameter - Zero Error, Tmin to Tmax = +/-30LSB.
What brings this error how it is possible to reduce her and up to what
value?
In how many time increases accuracy of transformation in all a band of
temperatures at use of such method of a temperature compensation as shown In
Figure 31. Use of the Temperature Sensor (Data Sheet AD7621_pre)?
Answer
The Zero error or Offset error is the difference between the ideal midscale
input voltage (0 V) and the actual voltage producing the midscale output code.
You can add or subtract a small voltage at the analog input to cancel this
error...or alternatively, once you know the offset at midscale , you can
software compensate for it.
By using the temperature sensor, you can software calibrate your digital output
to take into account changes in zero scale and full scale errors.
By knowing the ambient temperature of the board, and the temperature
co-efficient for the zero and gain error you can calibrate in your software the
digital o/p for changes over temperature for zero and full scale error.