In electronics, a data converter is a circuit that converts analog to digital or vice-versa. An A/D converter (or ADC) converts a continuously varying analog signal to a stream of digital numbers representing the signal at various points in time. A D/A converter (DAC) does the reverse.
Analog-to-Digital Converters (or A/D converters or ADCs) are circuits that convert analog signals into a stream of digital data.
The most common ADC architectures are successive-approximation-register (SAR), sigma-delta, integrating, flash (or direct conversion), pipelined, and two-step. For an introduction to these six types of ADCs, see Tutorial 2094: A Simple ADC Comparison Matrix.
Choosing the right ADC requires tradeoffs between resolution, channel count, power consumption, size, conversion time, static performance, dynamic performance, and price. For low-speed applications, a sigma-delta ADC is likely the best. Faster signals likely require a SAR ADC or pipeline ADC. For more information, see Tutorial 6139: Selecting the Right ADC for Your Application.
Digital-to-Analog Converters (or D/A converters or DACs) receive digital data (a stream of numbers) and output a voltage or current proportional to the value of the digital data.
When choosing a DAC, it is important to look at parameters such as linearity, resolution, speed, and accuracy. Other choices to keep in mind include serial vs. parallel interface, resolution/number of bits, number of input channels, and voltage or current output. For more information on choosing a DAC, see Tutorial 1055: Digital to Analog Converters are a “Bit” Analog and Tutorial 4025: DACs vs. Digital Potentiometers: Which is Right for My Application?Learn More: