I am using the MSP430F1611, and I am finding reading the internal temperature (ADC internal channel 10) does not appear to be very stable. I have setup the ADC12CLK to use a 32kHz ACLK and am using sample and hold of 64 ADC12CLK cycles (SHT_4). I am reading the internal temperature ADC at a rate of 1Hz and find the temperature varies as much as 20 to 30 degrees C ( as much as 200 ADC counts).
If I switch the ADC12CLK to use the internal ADC12 OSC, and change the samle and hold to 1024 (SHT_15), the readings seem a bit more stable, but I still see variations of 20 to 30 degrees over a period of time.
I understand the internal temp may not be all that acurate, but I assume is should be a bit more stable? Anyone seen similar issues? Is there a range of ADC12CLK frequencies that should be valid, i.e. running the ADC12CLK from ACLK 32kHz should not be an issue?
Thanks,
Don ...