Other Parts Discussed in Thread: LMZ12003,
I have 3 of these parts down on one board in different locations. I re-read the temp sensor values from any of the parts and I see digital values that change dramatically. For instance min/max over 10 reads (in hex)... 0x94 - 0xAC . This corresponds to 37-degC to 43-degC. The chips are powered from 5V with a 3.3V IOVDD. 5V comes from LMZ12003 (DC-DC converter), 3.3V comes from a linear regulator. The internal ADC reference is used. I have the recommended 4.7uF on REF_CMP. I tried changing the conversion time (from min of 00 to max of 11) but no effect.
Any thoughts? I could see a dithering of a couple LSBs, but this is huge. Could the act of reading cause the variation? Any suggestions to make this more stable?