What does an analog-to-digital converter output?

• A. A digital number
• B. An analog voltage
• C. A color value
• D. A sound sample

Answer: (A)

An analog-to-digital converter outputs a digital number that encodes the instantaneous amplitude of the analog input at each sampling moment. It samples the input voltage and quantizes that value into a finite set of discrete levels defined by its resolution, so the output is a stream of numbers rather than a continuous voltage. The higher the resolution, the more accurately those numbers represent the true analog level. While those digital numbers can later be used to reconstruct audio or color information, the converter’s direct output is the numerical code itself, not an analog voltage, nor a standalone color value or sound sample.