Which process converts a digital signal to an analogue signal?

Which process converts a digital signal to an analogue signal?

• A. A/D conversion
• B. Sampling
• C. Encoding
• D. D/A conversion

Answer: (D)

Converting a digital signal to an analogue signal means turning discrete numbers into a continuously varying waveform. The process that does this is digital-to-analogue conversion, which uses a DAC to map each digital value to a corresponding voltage level and—often with a reconstruction filter to smooth the steps—produce a smooth analogue signal suitable for driving speakers or other analogue devices. This is different from analogue-to-digital conversion, which captures an analogue signal as digital data; sampling is a step within digitizing that selects discrete time points from a continuous signal; encoding refers to representing information in a code, which may or may not involve converting to analogue but doesn’t itself convert digital data back to analogue.

Converting a digital signal to an analogue signal means turning discrete numbers into a continuously varying waveform. The process that does this is digital-to-analogue conversion, which uses a DAC to map each digital value to a corresponding voltage level and—often with a reconstruction filter to smooth the steps—produce a smooth analogue signal suitable for driving speakers or other analogue devices. This is different from analogue-to-digital conversion, which captures an analogue signal as digital data; sampling is a step within digitizing that selects discrete time points from a continuous signal; encoding refers to representing information in a code, which may or may not involve converting to analogue but doesn’t itself convert digital data back to analogue.