Forum Post: Reference voltage for ADC of TMS320F28335

Hi all,

In TMS320F2833x ADC reference guide i see only one formula for all reference voltage:

Digital Value = 0                                                                                                     , when input ≤ 0 V

Digital Value = 4096 * (Input Analog Voltage - ADCLO) / 3                           , when 0 V < input < 3 V

Digital Value = 4095                                                                                              , when input ≥ 3 V

    - So if i use 2.048 is reference voltage, i can use this formula and ADC input range is still 0V-3V.

    - If my ADC input only from 0V - 2.1V how can i configuration for 28335, and choose reference voltage to get formula: Digital Value = 4096 * (Input Analog Voltage - ADCLO) / 2.1                           , when 0 V < input < 2.1 V

Thanks and best regard