A digital-to-analog converter (DAC) maps a digital code to an analog output such as a voltage or current.

For an ideal $N$-bit unipolar DAC spanning output range $V_{range}$, adjacent codes differ by approximately

$$\Delta V=\frac{V_{range}}{2^N}.$$

Changing the digital code therefore changes the output in discrete steps rather than producing an arbitrarily precise analog value.

Practical DACs have limits such as output range, settling time, load capability and nonideal code-to-output relationships. An external buffer may be needed when the load requires more current than the converter can supply directly.

A sequence of DAC codes can produce a time-varying waveform. The update rate and output filtering then affect how much of the discrete stepping remains in the physical signal.

A DAC is the complementary boundary to an ADC: it turns finite digital representation back into a physical analog quantity.