Function of a demultiplexer – does a demultiplexer convert a binary or other code into a recognizable number or character for display, or is that the role of a decoder/driver?

Introduction / Context: Digital subsystems often include blocks with similar names but different roles. Demultiplexers and decoders are frequently confused. This question distinguishes a demultiplexer (DEMUX) from a decoder/driver that generates segment patterns for displays or translates codes into human-recognizable output.

Given Data / Assumptions:

• A demultiplexer routes a single input to one of many outputs based on select lines.
• A decoder maps binary codes to one-hot outputs or to display segments.
• Display drivers (for example, BCD-to-7-segment) convert numeric codes to segment patterns.

Concept / Approach: A DEMUX is a data-routing device: 1 input → N outputs, with only one output active at a time. It does not “interpret” the input data as a code. A decoder accepts an n-bit code and asserts exactly one of 2^n outputs, or generates a pattern (as in 7447/7448). Therefore, converting a code into a recognizable number or character is the job of a decoder/driver, not a demultiplexer.

Step-by-Step Solution:

Verification / Alternative check: 74HC238 (decoder) and 74HC154 (decoder) translate binary inputs to one-of-N outputs; 74HC4051 (analog MUX/DEMUX) simply routes signals and does not “recognize” codes beyond selection.

Why Other Options Are Wrong: Marking “Correct” confuses roles; references to BCD or 7447 drivers are about decoders, not demultiplexers; common-anode vs common-cathode pertains to 7-seg wiring, not DEMUX function.

Common Pitfalls: Assuming any device with select lines does decoding of data content; DEMUX only uses select lines to choose a path.

Final Answer: Incorrect