AD7799 AVDD Monitor 1.17V Internal Reference

Document created by analog-archivist Employee on Feb 23, 2016
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When monitoring a voltage on the AVDD pin, what is the accuracy/stability of
the 1.17V internal reference used for analog-digital conversion?


For the AVDD monitor, an internal untrimmed 1.17V reference is used. AVDD is
divided by 6 and the attenuated voltage is used as the ADC input. Since the
internal reference is untrimmed, the conversion which reflects the ADC voltage
is not accurate. The AVDD monitor gives a coarse result rather than an accurate
result. The error could be as large as 1%.