This issue was handled off-line, but I wanted to close the loop here in case other community members encounter the same issue. In this case, a precision voltage reference was used as the AVCC supply and a low-noise LDO was used as the DVCC supply. Unfortunately, the start-up profiles between these two supplies differed more than the absolute maximum of +/- 0.3V (+/- 0.1V during startup), which is shown in Sections 5.1 and 5.3 in the datasheet. Per Footnote 2, voltage differences between DVCC and AVCC exceeding this limit may cause malfunctions of the device. To resolve the issue, the LDO was used to supply both AVCC and DVCC along with a series resistor between them to help filter noise. Regards, James MSP Customer Applications
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