I have two different MCU's of cypress, CY8C4148AZI-S455 and CY8C4146AZI-S433, dealing with ADC_SAR_Seq.
I have noticed that I connected related ADC Pin to the ground, i.e short circuit, I saw 65535 ADC value on CY8C4148AZI-S455, and 20 ADC Value on CY8C4146AZI-S433 via uart protocol. What is the root-cause of such a difference ? Why am I acquring 65535 ADC value which is out of my range resolution (expecting min value ADC 0 and max value ADC 2047). I have attached top design configuration as below.
Any help would be appreciated.
Could you please check with "ADC_SAR_Seq_DieTemp" code example from the PSoC Creator and let us know your observations ?
If possible, please share your project so that we can check at our end.
Could you let me know if your input connections ? Are you grounding the input of the ADC through resistors ? Will you be able to share the analog front end connected to the ADC ?
Regarding on part of your question, "I saw 65535 ADC value on CY8C4148AZI-S455". This can happen if there is negative noise in your system.
See the extract from component datasheet. You can try changing your settings to keep Vref as VDDA/2, and single ended negative input as vref to get complete ADC resolution and see the results again.