In
electronics, a
digital-to-analog converter (
DAC,
D/A,
D2A or
D-to-A) is a function that converts digital data (usually binary) into an
analog signal (
current,
voltage, or
electric charge). An
analog-to-digital converter (ADC) performs the reverse function. Unlike analog signals,
digital data can be transmitted, manipulated, and stored without degradation, albeit with more complex equipment. But a DAC is needed to convert the digital signal to analog to drive an earphone or loudspeaker amplifier in order to produce sound (analog air pressure waves).