Encyclopedia Entry: 74HCT257DB,118

Product Overview

Category

The 74HCT257DB,118 belongs to the category of integrated circuits (ICs), specifically a quad 2-input multiplexer with 3-state outputs.

Use

This product is commonly used in digital electronics for data selection and routing applications. It allows multiple input signals to be selected and routed to a single output based on control signals.

Characteristics

• Quad 2-input multiplexer
• 3-state outputs
• High-speed operation
• Low power consumption
• Wide operating voltage range
• Compatibility with TTL inputs
• Schmitt-trigger action on all inputs

Package and Quantity

The 74HCT257DB,118 is available in a standard SOIC (Small Outline Integrated Circuit) package. It is typically sold in reels or tubes containing a specific quantity, such as 250 units per reel.

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 +125°C
• Propagation Delay: 10 ns (max)
• Output Current: ±6 mA

Pin Configuration

The 74HCT257DB,118 has a total of 16 pins, each serving a specific function:

1. A1: Input A1
2. B1: Input B1
3. Y1: Output Y1
4. G1: Enable Input G1
5. A2: Input A2
6. B2: Input B2
7. Y2: Output Y2
8. G2: Enable Input G2
9. VCC: Positive Power Supply
10. Y3: Output Y3
11. G3: Enable Input G3
12. B3: Input B3
13. A3: Input A3
14. Y4: Output Y4
15. GND: Ground
16. OE: Output Enable

Functional Features

The 74HCT257DB,118 offers the following functional features:

• Quad 2-input multiplexer: Allows selection of one out of four input signals.
• 3-state outputs: Enables high impedance state when not enabled, preventing interference with other devices.
• Schmitt-trigger action: Provides hysteresis for improved noise immunity and signal integrity.
• Compatibility with TTL inputs: Can be directly interfaced with TTL logic circuits.

Advantages and Disadvantages

Advantages

• High-speed operation allows for efficient data routing.
• Low power consumption minimizes energy usage.
• Wide operating voltage range provides flexibility in various applications.
• Schmitt-trigger action enhances noise immunity.
• Compatibility with TTL inputs simplifies integration with existing systems.

Disadvantages

• Limited to quad 2-input multiplexing functionality.
• May require additional components for complex routing scenarios.

Working Principles

The 74HCT257DB,118 operates based on the principles of digital multiplexing. It uses control signals to select one of the four input signals and routes it to the output. The enable inputs (G1, G2, G3) determine which input is active, while the output enable (OE) controls the output state. When not enabled, the outputs enter a high impedance state, allowing other devices to drive the bus.

Application Field Plans

The 74HCT257DB,118 finds applications in various fields, including: 1. Data communication systems 2. Digital signal processing 3. Industrial automation 4. Automotive electronics 5. Consumer electronics

Alternative Models

For similar functionality, the following alternative models can be considered: - 74HC257: Non-inverting quad 2-input multiplexer - 74LS257: Low-power Schottky quad 2-input multiplexer - CD4053B: Analog multiplexer/demultiplexer

These alternatives offer similar features and can be used as substitutes depending on specific requirements.

In conclusion, the 74HCT257DB,118 is a versatile integrated circuit that provides quad 2-input multiplexing functionality with 3-state outputs. Its high-speed operation, low power consumption, and compatibility with TTL inputs make it suitable for various digital electronics applications.