The Power of 2

In numerous types of analog position sensors, resolution is expressed in terms of bits, e.g, 8-bit, 12-bit, 16-bit, etc.  But what does that really mean?  In a previous entry, I discussed what I called Digitally Derived Analog Signals, which provides a basic overview of how Digital-to-Analog Converters (DAC’s) are used to generate analog sensor signals.  You may recall from that entry that when someone says a sensor has “16-bit resolution”, what they really mean is that the sensor employs a 16-bit DAC, which is capable of processing 216 discrete values, and representing any one of those values as a corresponding analog signal.

To help better understand what these binary numbers actually mean, I thought it might be helpful to provide a quick-reference chart showing the equivalent decimal values of numbers from 20 to 232.

(click to enlarge)The values in bold represent some of the more commonly used DAC’s for industrial sensors.