I need to measure 0 to 80V DC voltage with STM32F373CCT6 and I have some questions to get the best performance of the SDADC.
*Is this CPU and 16-bit SDADC good for this purpose?
*Is it better to use the internal 1V8 Vref or an external 1V8 or 3V3 Vref?
*In case I use an external 3v3 Vref I can insert a resistive divider to have a maximum of 3V3 at the SDADC input, such as a 1M series resistor and a 42k2 resistor to ground.
Do I need to put an op amp on SDADC input to have a low impedance input? The measured voltage is a stable DC voltage.
Using the internal analog gain can I increase the resolution of the ADC as the voltage decreases without external components?
*to calibrate the gain do I have to put a stable voltage at the analog input? what value should it have? does it have to go into the same pin I use to measure 0-80V DC or another analog input?
Thanks very much
