Description

The 74151 8-Line to 1-Line Data Selector / Multiplexer (MUX) is a versatile TTL logic IC designed to select one of eight input lines and route it to a single output line based on three binary select inputs. As part of the 7400 series logic family, the 74151 is widely used in digital circuits, signal routing, data acquisition systems, and microprocessor-based applications. Its standard 16-pin Dual Inline Package (DIP) allows for easy integration in both breadboard prototyping and PCB designs.

Multiplexers, like the 74151, are essential in digital design to reduce the number of data lines, simplify circuit design, and control multiple inputs efficiently. By combining multiple data sources into one output, the 74151 enables time-division multiplexing, logic selection, and controlled signal routing in complex systems.

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⚙️ Key Features:

• Function: 8-line to 1-line multiplexer / data selector

• Logic Family: TTL (Transistor-Transistor Logic)

• Inputs: 8 data inputs (D0–D7) + 3 select inputs (S0–S2)

• Output: Single data output (Y) + Active LOW output (Y̅)

• Enable Input: Active LOW to control multiplexer operation

• High-Speed Operation: Typical propagation delay ~22 ns

• Standard 16-Pin DIP Package: Easy for breadboard and PCB mounting

• Operating Voltage: 4.75V to 5.25V typical (5V TTL standard)

• Low Power Dissipation: Efficient and reliable operation

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🧩 Pin Configuration (16-Pin DIP):

This pinout allows easy routing of multiple signals to a single output, enabling efficient circuit design.

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⚡ Electrical Characteristics:

• Supply Voltage (VCC): 5V TTL standard

• Input High Voltage (VIH): ≥ 2V

• Input Low Voltage (VIL): ≤ 0.8V

• Output Current (IOL/IOH): ±8 mA typical

• Propagation Delay: ~22 ns typical

• Power Dissipation: ~10 mW per gate

These specifications make the 74151 suitable for high-speed digital logic and real-time signal selection applications.

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🧠 How It Works:

The 74151 multiplexer allows the selection of one input line (D0–D7) to pass through to the output based on the binary combination of select inputs (S0, S1, S2).

• When Enable (E̅) = LOW, the multiplexer operates normally.

• When Enable (E̅) = HIGH, the output Y is disabled (HIGH) and Y̅ is LOW, effectively turning off the multiplexer.

Truth Table:

The complementary output Y̅ provides the inverted version of the selected input, useful for logic operations and control circuits.

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🛠️ Applications:

• Digital Signal Routing: Select between multiple input lines for output

• Data Acquisition Systems: Multiplex sensor signals into a single microcontroller input

• Arithmetic Logic Units (ALUs): Controlled selection of operands

• Microprocessor and Microcontroller Interfaces: Efficient input management

• Digital Communication Systems: Time-division multiplexing

• Logic Design and Educational Kits: Teach MUX functionality and selection logic

• Control Systems: Simplify wiring by reducing multiple lines to a single output

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💡 Advantages:

• Reduces circuit complexity by combining multiple input signals

• TTL compatible for easy integration with 7400 logic ICs

• Fast propagation delay ensures high-speed operation

• Complementary output allows more flexible circuit design

• Easy to prototype with breadboards or PCBs

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📦 Package Includes:

• 1 × 74151 8-Line to 1-Line Data Selector / Multiplexer IC (DIP-16)

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📘 Conclusion:

The 74151 DIP 8-Line to 1-Line Data Selector / Multiplexer is a versatile, reliable, and high-speed IC ideal for signal selection, data routing, and logic control applications. Its TTL compatibility, complement output, and standard DIP packaging make it a perfect choice for both hobbyists and professional engineers working on digital electronics, embedded systems, and educational projects.