Flash ADC Resolution

A flash analogue-to-digital converter (ADC) is a type of converter that uses a resistor potential divider (PD), which feeds a series of operational amplifiers in comparator configuration. The LM3914 can be used as the basis of such a converter producing a linear conversion, because all of its internal resistors are the same value. Since there are ten resistors in the PD, it can compare ten different values using its comparators. The resolution is simply a division of the input voltage to the PD divided by ten in this case, because all the resistors in the PD are the same value. If the voltage at the high end (X in the diagram above) of the PD network were to be 5 V, then the resolution would be 0.5 V. If the voltage were to be 12 V, then the resolution would be 1.2 V.

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