Multiplexer (MUX)

A multiplexer (MUX) is a combinational logic circuit designed to switch one of several input lines to a single common output line by applying control signals. In industrial applications, particularly within Analog Front-End (AFE) systems, it enables multiple analog signals (e.g., from sensors, transducers) to be sequentially sampled and processed by a single analog-to-digital converter (ADC), reducing hardware complexity and cost. It operates based on digital selection inputs that determine which input channel is connected to the output, facilitating time-division multiplexing in data acquisition systems.

The multiplexer works by using digital control signals (select lines) to choose one input from multiple analog or digital inputs. Internally, it consists of logic gates (typically AND, OR, and NOT gates) that route the selected input to the output line. In AFE applications, it allows sequential sampling of multiple sensor signals, which are then processed through a shared ADC, optimizing signal integrity and system efficiency.