ADC (Analog-to-Digital Converter) is a device used to covert analog signals into digital forms for further processing. It is used widely in the domain of communication, medical, audio, measurement technology and other semiconductor fields.
An ADC is typically composed of a sample and hold circuit, analog signal Digitalization circuit, and a data output port. The sample and hold circuit holds the analog signal which is usually a voltage signal, and the Digitalization circuit is used for taking signal samples and converting them from an analog to a digital form. The converted digital signal is then sent to the data output port.
An ADC works by taking an analog signal such as a voltage signal and dividing the range of values of the signal into equal and manageable increments of individual numbers. This is done by a process called quantization. The signal is then taken and represented as a series of digital values, which are usually referred to as codes. Once the analog signal has been digitally encoded, a variety of digital signal processing techniques can be applied to it.
ADCs are usually characterized by the maximum sampling rate, resolution, and various other parameters which determine the accuracy and quality of conversion. For audio applications, such as music recording, the traditional way of ADC conversion is through the Pulse Code Modulation (PCM). This conversion usually uses 14-16 bits of resolution and sampling rates of 44,100 Hz to obtain a highly accurate digital representation of the analog signal.
In modern applications, due to the high demand of accuracy and speed, numerous techniques have been developed such as Delta-Sigma Converters, oversampling sigma-delta modulators, and multibit sigma-delta modulators which allow higher resolution and faster sampling rates for high-precision data acquisition.