Encyclopedia Entry: 74AC139PC

Product Overview

Category

The 74AC139PC belongs to the category of integrated circuits (ICs) and specifically falls under the family of digital logic multiplexers/demultiplexers.

Use

This product is commonly used in digital electronic systems for data routing and selection purposes. It acts as a multiplexer or demultiplexer, allowing multiple input signals to be directed to a single output or vice versa.

Characteristics

• The 74AC139PC operates on a supply voltage range of 2V to 6V.
• It offers high-speed performance with low power consumption.
• This IC has two independent 2-to-4 line decoders with active-low outputs.
• It features fully buffered inputs and outputs for improved noise immunity.
• The device is designed to be compatible with TTL (Transistor-Transistor Logic) and CMOS (Complementary Metal-Oxide-Semiconductor) logic families.

Package and Quantity

The 74AC139PC is available in a 16-pin dual in-line package (DIP). Each package contains one unit of the IC.

Specifications

• Supply Voltage Range: 2V to 6V
• Input Voltage Range: 0V to VCC
• Output Voltage Range: 0V to VCC
• Operating Temperature Range: -40°C to +85°C
• Maximum Propagation Delay: 7 ns
• Maximum Quiescent Current: 8 mA

Pin Configuration

The 74AC139PC has a total of 16 pins, which are assigned specific functions as follows:

1. GND (Ground)
2. A0 (Address Input 0)
3. A1 (Address Input 1)
4. E1 (Enable Input 1)
5. Y0 (Output 0)
6. Y1 (Output 1)
7. G1 (Gated Enable Input 1)
8. VCC (Positive Power Supply)
9. Y2 (Output 2)
10. Y3 (Output 3)
11. E2 (Enable Input 2)
12. A2 (Address Input 2)
13. A3 (Address Input 3)
14. G2 (Gated Enable Input 2)
15. NC (No Connection)
16. GND (Ground)

Functional Features

The 74AC139PC offers the following functional features:

• Two independent 2-to-4 line decoders with active-low outputs.
• Buffered inputs and outputs for improved noise immunity.
• High-speed operation suitable for various digital applications.
• Compatibility with both TTL and CMOS logic families.

Advantages and Disadvantages

Advantages

• High-speed performance allows for efficient data routing and selection.
• Low power consumption contributes to energy-efficient designs.
• Compatibility with multiple logic families enhances versatility in system integration.
• Buffered inputs and outputs improve noise immunity, ensuring reliable signal transmission.

Disadvantages

• Limited number of input and output lines may restrict the complexity of certain applications.
• The active-low output configuration may require additional circuitry for specific use cases.

Working Principles

The 74AC139PC operates based on the principles of digital logic multiplexing and demultiplexing. It uses address inputs to select one of the multiple input lines and directs it to the corresponding output line based on the control signals provided. The active-low outputs enable the selected output line while keeping the others inactive.

Application Field Plans

The 74AC139PC finds extensive application in various digital systems, including but not limited to: - Data routing and selection in microprocessors and microcontrollers. - Address decoding in memory systems. - Signal routing in communication devices. - Control signal generation in industrial automation. - Logic circuit design and prototyping.

Alternative Models

Several alternative models with similar functionality to the 74AC139PC include: - 74HC139: A CMOS logic family equivalent with a wider supply voltage range. - 74LS139: A TTL logic family equivalent with slightly slower speed but higher output current capability. - CD74AC139: Another CMOS logic family equivalent with improved noise immunity.

These alternative models can be considered based on specific project requirements, compatibility needs, and availability.

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