ADC Delsig Question | Cypress Semiconductor
ADC Delsig Question
In my design I am trying to use to the ADC Delsig to measure the battery capacity of an on-board battery in my system by converting the battery input voltage to a digital value using the ADC Delsig component in the PSoC and then calculating the remaining battery life based on the output.
The battery I am measuring has an input range to the PSoC of 2.2 - 2.8 VDC. My board has Vdda connected to +5VDC, so I configure the input range of the delsig to be single ended with an input range of "Vssa to Vdda." However, when I make these settings, the Vref of the delsig is automatically set to "Internal Vdda / 4" or 1.25 volts.
How can the ADC delsig accurately measure a voltage input range of Vssa to Vdda when the reference voltage for the ADC is set to Vdda / 4? Doesn't the reference voltage for the ADC need to be greater than the maximum input voltage?