Encyclopedia Entry: 74HCT245D

Product Overview

Category

The 74HCT245D belongs to the category of integrated circuits (ICs) and specifically falls under the family of bus transceivers.

Use

This IC is primarily used for bidirectional level shifting and voltage translation between different logic levels in digital systems. It enables seamless communication between devices operating at different voltage levels.

Characteristics

• Bidirectional data transfer capability
• Wide operating voltage range
• High-speed operation
• Low power consumption
• Compatibility with TTL and CMOS logic families
• Robust protection against electrostatic discharge (ESD)

Package

The 74HCT245D is available in a standard 20-pin dual in-line package (DIP), which facilitates easy integration into circuit boards.

Essence

The essence of the 74HCT245D lies in its ability to enable efficient and reliable data transfer between devices operating at different voltage levels, ensuring compatibility and seamless communication.

Packaging/Quantity

The 74HCT245D is typically packaged in reels or tubes, containing a quantity of 25 or 50 units per package.

Specifications

• Supply Voltage Range: 4.5V to 5.5V
• Input Voltage Range: 0V to VCC
• Output Voltage Range: 0V to VCC
• Maximum Operating Frequency: 40 MHz
• Propagation Delay Time: 11 ns (max)
• Input Capacitance: 3.5 pF (typ)
• Output Capacitance: 6 pF (typ)
• Operating Temperature Range: -40°C to +85°C

Detailed Pin Configuration

The 74HCT245D has a total of 20 pins, each serving a specific function. The pin configuration is as follows:

1. OE (Output Enable) - Output Enable Control
2. A1 - Data Input/Output A1
3. B1 - Data Input/Output B1
4. A2 - Data Input/Output A2
5. B2 - Data Input/Output B2
6. A3 - Data Input/Output A3
7. B3 - Data Input/Output B3
8. GND (Ground) - Ground Reference
9. B4 - Data Input/Output B4
10. A4 - Data Input/Output A4
11. B5 - Data Input/Output B5
12. A5 - Data Input/Output A5
13. B6 - Data Input/Output B6
14. A6 - Data Input/Output A6
15. VCC - Power Supply Voltage
16. DIR (Direction Control) - Direction Control Input
17. B7 - Data Input/Output B7
18. A7 - Data Input/Output A7
19. B8 - Data Input/Output B8
20. A8 - Data Input/Output A8

Functional Features

• Bidirectional data transfer: The 74HCT245D allows for the bidirectional transfer of data between two buses, ensuring seamless communication.
• Voltage level translation: It facilitates the conversion of logic levels between different voltage domains, enabling compatibility between devices operating at different voltages.
• Output enable control: The OE pin allows for the activation or deactivation of the output drivers, providing flexibility in controlling data flow.
• Direction control: The DIR pin determines the direction of data transfer, allowing for easy switching between input and output modes.

Advantages and Disadvantages

Advantages

• Wide operating voltage range enables compatibility with various logic families.
• High-speed operation ensures efficient data transfer.
• Low power consumption contributes to energy efficiency.
• Robust ESD protection enhances reliability.
• Compact package facilitates easy integration into circuit boards.

Disadvantages

• Limited number of input/output channels (8-bit bidirectional data transfer).
• Propagation delay may affect real-time applications with strict timing requirements.

Working Principles

The 74HCT245D operates based on the principles of voltage level translation and bidirectional data transfer. It utilizes a combination of transistors, resistors, and logic gates to achieve efficient signal conversion between different voltage domains. The direction of data flow is controlled by the DIR pin, while the OE pin enables or disables the output drivers.

Detailed Application Field Plans

The 74HCT245D finds extensive application in various digital systems, including but not limited to: - Microcontroller interfacing - Data communication protocols (e.g., I2C, SPI) - Level shifting in mixed-voltage systems - Bus buffering and isolation - Signal conditioning in industrial automation

Detailed and Complete Alternative Models

There are several alternative models available that offer similar functionality to the 74HCT245D. Some notable alternatives include: - SN74LVC245A: