In digital electronics, which device has a single data input line and routes that signal to one of many outputs (i.e., one input and many outputs)?

Introduction / Context:
A core concept in digital systems is signal routing. Two complementary building blocks are the multiplexer (many inputs, one output) and the demultiplexer (one input, many outputs). Knowing which block does what is essential for designing data paths, addressing memory, and distributing clocks or control signals.

Given Data / Assumptions:

• The question asks specifically for a device with one input and many outputs.
• Standard logic families and definitions are assumed (no exotic custom logic).

Concept / Approach:

A demultiplexer (DEMUX) accepts a single data input and, based on select lines, connects that input to exactly one of several outputs. By contrast, a multiplexer (MUX) funnels one of many inputs to a single output. Flip-flops and counters are sequential elements, not routing elements; encoders perform the inverse of decoders but still do not match “one input, many outputs”.

Step-by-Step Solution:

Verification / Alternative check:

Textbook truth tables confirm that a 1-to-4 DEMUX has one data input, two select lines, and four outputs; only one output reflects the input at a time.

Why Other Options Are Wrong:

• Multiplexer: many inputs to a single output (opposite direction).
• Counter: sequential state machine, not a router.
• Flip-flop: 1-bit storage, not a router.
• Encoder: many inputs to fewer coded outputs, not one-to-many.

Common Pitfalls:

Confusing MUX and DEMUX due to their complementary nature; forgetting the role of select lines that steer the single input to a chosen output in a DEMUX.

Final Answer:

Demultiplexer