1×8 DEMULTIPLEXER

1 Data Input • 3 Select Lines • 8 Outputs
PrayogSetu
🎛️ Input & Control Panel
Operation Mode
Data Input
Data Input (D) Input signal stream
HIGH
Select Lines (3 Bits)
Select S2 (MSB) Bit 2 (Weight 4)
0
Select S1 Bit 1 (Weight 2)
0
Select S0 (LSB) Bit 0 (Weight 1)
0
Auto Routing Demo
Routing Speed 1000 ms
⚡ Circuit Schematic Workspace
Data Input (D) D = 1 S2 0 S1 0 S0 0 Select Lines (S2 S1 S0) 1 × 8 DEMUX Demultiplexer D Y0 Y0 Y1 Y1 Y2 Y2 Y3 Y3 Y4 Y4 Y5 Y5 Y6 Y6 Y7 Y7
CURRENT OPERATION
ROUTING TO Y0
Selected output receives input data D
📊 Output & State Monitor
Selected Output S2 S1 S0 = 000
Y0 VALUE: 1
Complete Output Vector [Y7–Y0]
Y70
Y60
Y50
Y40
Y30
Y20
Y10
Y01
Individual Line Monitors
Y0 D · S2̅ · S1̅ · S0̅ LOGIC 1
Y1 D · S2̅ · S1̅ · S0 LOGIC 0
Y2 D · S2̅ · S1 · S0̅ LOGIC 0
Y3 D · S2̅ · S1 · S0 LOGIC 0
Y4 D · S2 · S1̅ · S0̅ LOGIC 0
Y5 D · S2 · S1̅ · S0 LOGIC 0
Y6 D · S2 · S1 · S0̅ LOGIC 0
Y7 D · S2 · S1 · S0 LOGIC 0
📋 Selection Truth Table & Logic Equations
S2 S1 S0 Selected Output Boolean Minterm Equation Current Value (D=1)
000 Y0 Y0 = D · S2̅ · S1̅ · S0̅ 1
001 Y1 Y1 = D · S2̅ · S1̅ · S0 0
010 Y2 Y2 = D · S2̅ · S1 · S0̅ 0
011 Y3 Y3 = D · S2̅ · S1 · S0 0
100 Y4 Y4 = D · S2 · S1̅ · S0̅ 0
101 Y5 Y5 = D · S2 · S1̅ · S0 0
110 Y6 Y6 = D · S2 · S1 · S0̅ 0
111 Y7 Y7 = D · S2 · S1 · S0 0

* Selected Output receives Data Input D. All 7 unselected output lines are held at Logic 0.

📚 Educational Theory & Industrial Applications

What is a 1×8 Demultiplexer?

A 1×8 Demultiplexer (DEMUX) is a combinational digital logic circuit that takes a single data input line (D) and routes it to any one of eight output lines (Y0 through Y7).

Why are 3 Select Lines Required?

To uniquely select one of N output lines, a demultiplexer requires m control select lines such that:

2m = N  ⇒  23 = 8 Outputs

The 3 select lines (S2, S1, S0) form a 3-bit binary address range from 0002 to 1112, addressing outputs Y0 to Y7 respectively.

Multiplexer (MUX) vs. Demultiplexer (DEMUX)

Feature 8×1 Multiplexer (MUX) 1×8 Demultiplexer (DEMUX)
Primary Function Data Selector (Many to One) Data Distributor (One to Many)
Inputs & Outputs 8 Inputs → 1 Output 1 Input → 8 Outputs
Select Lines 3 Select Lines (S2, S1, S0) 3 Select Lines (S2, S1, S0)
Analogy Multi-position Rotary Switch Distributor Rotor Switch

Industrial Applications

  • Time Division De-multiplexing (TDM): Reconstructs original parallel channels from a single high-speed serial stream in telecom.
  • Memory Bank Decoding & Addressing: Directs write-enable and chip-select signals to specific memory IC blocks.
  • Serial-to-Parallel Data Converters: Feeds incoming serial bitstreams into parallel registers or 8-bit output ports.
  • Data Acquisition Systems (DAS): Routes master sensor calibration pulses to 8 targeted measurement channels.