Encyclopedia Entry: 74AC257SCX

Product Overview

Category

The 74AC257SCX belongs to the category of integrated circuits (ICs) and specifically falls under the family of digital multiplexers.

Use

This product is primarily used in digital electronic systems for data selection and routing purposes. It allows multiple input signals to be selectively routed to a single output line, based on control inputs.

Characteristics

• High-speed operation: The 74AC257SCX offers fast switching times, making it suitable for applications requiring quick data selection.
• Low power consumption: This IC is designed to operate efficiently with low power requirements.
• Wide operating voltage range: It can function within a broad range of supply voltages, typically between 2V and 6V.
• Compatibility: The 74AC257SCX is compatible with both TTL and CMOS logic families, ensuring seamless integration into various digital systems.

Package and Quantity

The 74AC257SCX is available in a small outline package (SOIC) with 16 pins. It is commonly sold in reels or tubes containing multiple units, with quantities varying depending on the supplier.

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: 10 ns
• Maximum Power Dissipation: 500 mW

Pin Configuration

The 74AC257SCX features 16 pins arranged as follows:

┌───┐ A1 -|1 16|- Vcc B1 -|2 15|- Y C1 -|3 14|- GND D1 -|4 13|- C A2 -|5 12|- B B2 -|6 11|- A C2 -|7 10|- G D2 -|8 9|- F └───┘

Functional Features

The 74AC257SCX is a quad 2-input multiplexer with output enable. It allows the selection of one of four data inputs (A, B, C, or D) to be routed to the output pin (Y) based on the control inputs (G and C). The output enable input (E) enables or disables the output.

Advantages and Disadvantages

Advantages

• High-speed operation enables efficient data selection in time-critical applications.
• Low power consumption contributes to energy-efficient system designs.
• Wide operating voltage range enhances compatibility with various digital systems.
• Compact package size facilitates integration into space-constrained designs.

Disadvantages

• Limited number of input channels (four) may restrict its use in applications requiring more extensive data routing capabilities.
• Lack of built-in protection features against electrical faults or ESD events may require additional external circuitry for robustness.

Working Principles

The 74AC257SCX operates by utilizing internal logic gates to decode the control inputs and select the appropriate data input to be routed to the output. When the control inputs are set accordingly, the selected data input appears at the output pin. The output enable input allows the user to enable or disable the output as needed.

Application Field Plans

The 74AC257SCX finds applications in various digital systems, including but not limited to: - Data multiplexing in communication systems - Address decoding in memory devices - Input selection in microcontrollers - Signal routing in audio/video equipment

Alternative Models

For similar functionality, alternative models to the 74AC257SCX include: - 74HC257: A CMOS-based quad 2-input multiplexer with output enable. - CD4053: A CMOS analog multiplexer/demultiplexer IC with three control inputs and eight channels.

These alternatives offer comparable features and can be considered based on specific application requirements.

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