Importance to be in Full Scale for ADC

Better resolution.

Hope This Helps! Rich

--- Because you'll lose resolution if you aren't.

Consider:

If you have an 8 bit ADC with an input range of zero to one volt it'll output 00000000 with an input of 0V and 11111111 with an input of 1V.

If you have a signal which varies from zero to 0.5V and you connect it to the ADC input, then the best you'll ever get out of the ADC will be

01111111, so instead of being able to resolve 256 different states corresponding to input voltages you'll only be able to resolve 128.

In some applications it may not be important, but for those where it is the usual route is to amplify the signal so that it covers the full-scale input of the ADC or to select the ADC reference so that the input signal's excursion causes a full-scale change in the ADC output.

JF

Thank you, Rich.

Hi! JF,

Thank you the detailed explanation.