Encyclopedia Entry: 74F251ASJ

Product Overview

Category

The 74F251ASJ belongs to the category of integrated circuits (ICs) and specifically falls under the family of multiplexers/demultiplexers.

Use

This IC is primarily used for data selection and routing purposes in digital electronic systems. It enables the connection of multiple input signals to a single output line, or vice versa.

Characteristics

• The 74F251ASJ is a high-speed, quad 2-input multiplexer with three-state outputs.
• It operates on a supply voltage range of 4.5V to 5.5V.
• This IC offers low power consumption and high noise immunity.
• It is designed to be compatible with various TTL families.

Package and Quantity

The 74F251ASJ is available in a 16-pin plastic dual in-line package (PDIP). It is commonly sold in reels or tubes containing multiple units.

Essence

The essence of the 74F251ASJ lies in its ability to efficiently route and select data signals within digital systems, providing flexibility and control over information flow.

Specifications

• Supply Voltage Range: 4.5V to 5.5V
• Input Voltage Range: 0V to Vcc
• Output Voltage Range: 0V to Vcc
• Operating Temperature Range: -40°C to +85°C
• Propagation Delay Time: 7 ns (typical)
• Output Current: ±24 mA

Pin Configuration

The 74F251ASJ features a 16-pin configuration as follows:

+---+--+---+ A1 --|1 +--+ 16|-- Vcc B1 --|2 15|-- Y C1 --|3 14|-- GND D1 --|4 13|-- A0 A2 --|5 12|-- A1 B2 --|6 11|-- A2 C2 --|7 10|-- OE D2 --|8 9|-- B +----------+

Functional Features

• Quad 2-input multiplexer: Allows selection of one out of four input lines based on control inputs.
• Three-state outputs: Provides the ability to disconnect the output from the bus, allowing multiple devices to share the same bus without interference.
• High-speed operation: Enables efficient data routing in time-critical applications.
• TTL compatibility: Ensures seamless integration with various TTL logic families.

Advantages and Disadvantages

Advantages

• High-speed operation facilitates rapid data selection and routing.
• Low power consumption contributes to energy-efficient designs.
• Three-state outputs allow for bus sharing and reduce signal interference.
• Wide supply voltage range enhances compatibility with different systems.

Disadvantages

• Limited number of input lines (four) may restrict certain complex applications.
• Propagation delay time may introduce timing constraints in high-frequency systems.
• Availability and pricing may vary depending on market demand and supplier stocks.

Working Principles

The 74F251ASJ operates by utilizing its control inputs (A0, A1, A2) to select one of the four input lines (A1, B1, C1, D1) and route it to the output pin (Y). The OE (Output Enable) pin controls the three-state outputs, enabling or disabling the connection between the output and the bus. This IC functions based on digital logic principles, employing transistors and gates to perform the necessary data selection and routing operations.

Application Field Plans

The 74F251ASJ finds extensive use in various digital electronic systems, including but not limited to: - Data multiplexing in microprocessors and microcontrollers. - Address decoding in memory systems. - Signal routing in communication devices. - Input/output selection in digital switches and routers. - Control signal routing in industrial automation systems.

Alternative Models

For those seeking alternatives to the 74F251ASJ, several similar ICs are available on the market. Some notable options include: - SN74LS157: Quad 2-input multiplexer with three-state outputs. - CD4051B: Single 8-channel analog multiplexer/demultiplexer. - MC14051B: Quad 2-channel analog multiplexer/demultiplexer.

These alternative models offer similar functionality and can be considered based on specific application requirements.

In conclusion, the 74F251ASJ is a versatile quad 2-input multiplexer IC that provides efficient data selection and routing capabilities. Its high-speed operation, low power consumption, and compatibility with various TTL families make it suitable for a wide range of digital electronic applications.