TMS320F280049: Tolerance of the ADC Sampling switch resistance, Sampling capacitor, and parasitic input capacitance

Hi Wilson,

Please use 20% tolerance for all values (see: https://e2e.ti.com/support/microcontrollers/c2000/f/171/t/783882?tisearch=e2e-sitesearch&keymatch=tolerance).  

hi Devin,

For ADC sampling switch resistance, I thought resistance would not deviate so much as capacitance.

A typical 500 Ohm of ADC sampling switch resistance having a 20% tolerance would be surprisingly a lot!.

I thought the usual tolerance would be somewhere 2% or 5% ?

Hi Wilson,

The resistor is just for modeling purposes; it doesn't physically exit.  Overall, the ADC is more complicated and the input model is provided as a useful predictor of settling times.   

Hi Devin,

Thanks for the clarification.

regards

Wilson Pang.