Other Parts Discussed in Thread: TMS320F28377D
Hello Team,
I have a customer who have questions with respect to the ADS1209 :
For example If we apply 1VDC between (CHA+ and CHA-) , we expect to read a raw value of (1V * (2^16)/5V) = 13107 counts through the TMS320F28377DPTPS.
But the data that we actually read is 12058 counts.
Page 3 of the datasheet under FSR, the Specified Differential input voltage range is Vref * 0.92. With this calculation the count of 12058 seems correct. Can someone explain me what this spec actually means and how the value of 0.92*Vref was determined.
From what I understand while reviewing the Sigma delta converters for MSP430 in previous cases is it should be something like this :
Input voltage range of 100% of the FSR, 1.00* |Ch+ - Ch-| <= 1.00*Vref = 1.151 V
Input voltage range of 80% of the FSR, 0.80* |Ch+ - Ch-| <= 0.80*Vref = 0.80*1.151 V = 0.921 V
Beyond these 80%, the specified performance isn't guaranteed. So if you exceed them, your results are less reliable.
Is the understanding correct?
Thank you for your time.
Kishen