Hi,
I am using this ADC to calculate the voltages that are in the range of 0.9V to 12V.I am able to perform the offset and gain calibartion on the ADS125H02.
Offset calibration procedure:
I have enabled the Internal short to VCOM in mode4 register and given the offset calibration command and the offset calibration registers are getting updated by ADC.
Gain calibration procedure:
I have taken the 5vref as an input and set the pga gain as 0.5 and issued the gain calibration command and the gain calibration registers are getting updated by ADC.
After that calibration sequence is done I am setting the pga gain as 0.125 and taken all the readings from the voltages that are in the range of 0.9V to 12V.
For 12V I am getting only the 10.6V. For 1.8V I am getting only 1.7V .For 0.9V I am getting the 0.83V.
Why the voltages are getting this differnce even after performing the calibrations?
Is there any solution for this problem??
I just want to know that is there any internal voltage that can be used for the calibration of the ADC.