Analog to digital conversion chip and digital to analog conversion chip. An analog-to-digital converter, A/D converter, or ADC, is usually used to convert an analog signal into a digital signal, converting an input voltage signal into an output digital signal. The digital-to-analog converter is the D/A converter, referred to as DAC, which is the device that converts the digital quantity into analog. It is commonly used as the output channel of the process control computer system, which is connected with the actuator to realize the automatic control of the production process.