ADS8556 getting hot

Hi Sham,

I've split this ADS8556 post off from the original because we're sort of beyond the original topic (lower eight bits not toggling).  So now you have an analog input channel that stopped working and you have the ADS8556 device getting hot when you apply an analog input.  This definitely sounds like you've done some physical damage to the device on the board and would explain the erroneous conversion results you mentioned.

The only way I know of to damage an input channel (besides the normal ESD type issues or errant probing problems) is if the analog input is applied to the device without having the HV rails applied to the part.  If the input range was not configured correctly, you would either saturate the conversion results or you would get half the expected value.  As long as the HVdd and HVss rails are applied though, this would not damage the silicon.

Using an external reference while the internal reference is enabled could potentially damage something, but that would be seen across all channels, not just one channel pair.   If you have the ability to remove and replace the ADS8556 device from the EVM, you can apply for sample chips and I suspect you will be back in business.