CD74AC257E

Product Overview

• Category: Integrated Circuit (IC)
• Use: Data Selector/Multiplexer
• Characteristics: High-speed, low-power consumption
• Package: 16-pin DIP (Dual In-line Package)
• Essence: CD74AC257E is a quad 2-input multiplexer with 3-state outputs.
• Packaging/Quantity: Available in tubes of 25 units or reels of 2,500 units.

Specifications

• Logic Family: AC
• Number of Inputs: 8 (4 inputs per multiplexer)
• Number of Outputs: 4
• Output Type: 3-state
• Operating Voltage Range: 2V to 6V
• Propagation Delay: 5ns (typical)
• Operating Temperature Range: -40°C to +85°C

Detailed Pin Configuration

The CD74AC257E has a total of 16 pins. The pin configuration is as follows:

1. A0: Input A0 for the first multiplexer
2. B0: Input B0 for the first multiplexer
3. Y0: Output Y0 for the first multiplexer
4. G1: Enable input for the first multiplexer
5. A1: Input A1 for the second multiplexer
6. B1: Input B1 for the second multiplexer
7. Y1: Output Y1 for the second multiplexer
8. G2: Enable input for the second multiplexer
9. VCC: Positive power supply
10. Y3: Output Y3 for the fourth multiplexer
11. GND: Ground
12. B3: Input B3 for the fourth multiplexer
13. A3: Input A3 for the fourth multiplexer
14. Y2: Output Y2 for the third multiplexer
15. G3: Enable input for the third multiplexer
16. B2: Input B2 for the third multiplexer

Functional Features

• CD74AC257E is designed to select one of four data inputs and route it to a single output based on the control inputs.
• It features 3-state outputs, allowing multiple devices to share the same bus without interference.
• The device operates at high speed and consumes low power, making it suitable for various applications.

Advantages and Disadvantages

Advantages

• High-speed operation enables efficient data selection.
• Low-power consumption helps in reducing overall system energy requirements.
• 3-state outputs allow for easy bus sharing between multiple devices.

Disadvantages

• Limited number of inputs and outputs may restrict its use in complex systems.
• Operating voltage range may not be suitable for all applications.

Working Principles

The CD74AC257E works by using the control inputs (G1, G2, G3) to select one of the four data inputs (A0, A1, A2, A3) and route it to the corresponding output (Y0, Y1, Y2, Y3). When the enable input (G1, G2, G3) is high, the selected input is passed to the output. When the enable input is low, the output is in a high-impedance state (3-state), allowing other devices to drive the bus.

Detailed Application Field Plans

CD74AC257E can be used in various applications, including:

1. Data multiplexing in digital communication systems.
2. Address decoding in memory systems.
3. Bus switching in computer architectures.
4. Signal routing in test and measurement equipment.
5. Control signal selection in industrial automation.

Detailed and Complete Alternative Models

Some alternative models to CD74AC257E include:

1. SN74HC257: Similar quad 2-input multiplexer with 3-state outputs, but operates at a different logic family (HC).
2. CD74ACT257: Quad 2-input multiplexer with 3-state outputs, operating at a different logic family (ACT) and offering improved speed and power characteristics.
3. CD74HCT257: Quad 2-input multiplexer with 3-state outputs, operating at a different logic family (HCT) and providing compatibility with TTL logic levels.

These alternative models offer similar functionality but may have differences in terms of speed, power consumption, and voltage compatibility.

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