Money for nothing.
Need help --- suffering major brain strain. Consider the following .....
It should be simple to set up a series of muxed voltage divider networks such that the V+ and V- pins of a fully differential 10 bit analog to digital converter can be switched thus (say): 1 to 2 volts, 2 to 3 volts, 3 to 4 volts, and 4 to 5 volts i.e. they have a zero to1 volt (say) range between the V+ and V- inputs. (I know other factors come into it --- I'm trying to create a simplified scenario).
Now suppose Vref is then set at 1 volt.
Therefore each one volt sub-range is capable of a resolution of 1 mV i.e. the 1000 steps are divided between (depending on which setup is switched in) 1 and 2 volts, 2 & 3 volts, 3 & 4 volts etc. etc.
So with the addition of a mux and a little programming logic, one can get around 1.25 mV resolution from a 5 volt 10 bit ADC over the WHOLE 5 VOLT RANGE instead of, as would normally occur, 5 mV resolution. A cheap 10 bit ADC acts as a 12 bit ADC.
Experts have told me the above is twaddle. Is this so?