Sometimes an ADC is needed to monitor only a voltage window. For example does the voltage of a 12V Pb-Battery never exceed 14.4V (V_MAX) and should never go below 10.5V (V_MIN). Voltages outside this range could damage the accumulator permanently. When using an ADC with single ended inputs you'll always monitor the complete voltage range of 0V to V_MAX. With differential ADC inputs it is possible to only monitor the desired voltage range of V_MIN to V_MAX. The advantage of this method is that you get a higher ADC resolution for the desired
input range. How this can be achieved is described in the attached pdf file.
Note that that the paper doesn't cover ADC functionality. Before reading you should have understood how an ADC with differential inputs operates.
In addition I have attached my "Electronics Calculator". This tool can help to select the right resistor values. How to use it is explained in the PDF file, too. The "Electronics Calculator" is a Microsoft Excel workbook. It contains macros. Thus you have to enable macros to make use of the tool. I have programmed the "Electronics Calculator" in MS Excel 2007. It may work with older versions. Maybe someone could check it and post his/her experience here.
I'm no native english speaker. So the PDF could be brimfull of nasty misspelling. It would be nice if someone could proofread the PDF and PM me the corrections. I'll update the PDF then.