Orginal link is here: https://e2e.ti.com/support/data-converters/f/73/t/710943?tisearch=e2e-sitesearch&keymatch=ADS7830
If you plan to monitor 3.3V rail directly then you can either use external reference >3.3V and VDD>3.3V to get correct ADC reading. The other way is to use resistive divide on 3.3V rail similar to one used on 12V rail to get the input within ADC full scale range
Hi
If I want to use ADS7830 to monitor a voltage that was above vref scale (for example Vin >5V) , I would use a resistive divider, but I can't find any information of the impedance of analog input channel in ADS7830 datasheet, so how do I select the resistor of the divider to scale the voltage precisely?
regards
Chenhui