A multiplexer (MUX) is a device that can synthesize a single output signal from multiple input signals in a way that is recoverable for each input signal. Data from multiple sources is transmitted on a single transmission line using the straight forward logic function of choosing and routing.

A multiplexer can be thought of an electronic switch as shown in fig.

A multiplexer has

1. Data inputs: The binary logic levels or data are entered through the data inputs and switched to the multiplexer's output. Multiple data inputs can be switched to the output at once using a multiplexer, but only one data input can be switched at a time.

2. Select inputs: The multiplexer's address inputs are the select inputs. Data input is switched to the output is determined by the address on the select inputs. Each data input needs its own address, which is a distinct binary combination supplied on some inputs.

3. Output: The multiplexer is programmed through the select inputs to establish a connection between output and addressed data input.

Application of Multiplexer

Multiplexers are versatile circuit that are used in application such as

a. Data selection: The data from only one device is selected to be transmitted on the common channel at a given time but multiplexer can address any of the device output when necessary. This application is referred to as data selection, is commonly used to reduce the cost of separate transmission facilities.

b. Cascaded operation: Multiplexers can be cascaded together to increase the number of data inputs that can be transferred to a single output. Cascading is a technique where several MUX chips are wired to work together.

c. Binary word multiplexing: Binary word multiplexing is an application where all the bits of binary words are switched in parallel or simultaneously through a MUX circuit. Binary words are typically a 4 bit nibble or a 8 bit byte.

d. Time division multiplexing: Digital transmission systems heavily rely on the sophisticated data selection technique known as time division multiplexing. It is widely used in both public and commercial telephone networks to transmit several audio and video data streams over a single transmission line. Many devices share a single transmission line in applications that use time division multiplexing. Each unit sharing the transmission line is given a specific time slot for data transfer. One slot of data from each device is included in a frame that holds the output multiplexed data.

This note is taken from Classical Mechanics, MSC physics, Nepal.

This note is a part of the Physics Repository.