The CD74ACT138E is a high-performance, low-power 3-to-8 line decoder/demultiplexer that is designed to decode three binary inputs into eight outputs. It is part of the Harris Corporation's series of integrated circuits (ICs) that utilize advanced CMOS technology, making it suitable for a variety of digital applications. This device is especially useful in memory address decoding, data routing, and multiplexing applications.

## Key Features

1. Decoding Capability:
- The CD74ACT138E can take three binary inputs and generate eight mutually exclusive outputs. When one of the inputs is activated, the corresponding output goes low (active), while all other outputs are held high (inactive).

2. Low Power Consumption:
- Designed using Advanced CMOS technology, the CD74ACT138E operates with low static and dynamic power consumption, making it an energy-efficient choice for modern digital circuits.

3. Wide Operating Voltage Range:
- The device supports a wide range of operating voltages, typically from 4.5V to 5.5V, accommodating various logic levels.

4. High Speed:
- With propagation delays as low as 7 ns (typical at 5V), the CD74ACT138E is capable of fast switching, making it ideal for high-speed applications.

5. Tri-state Outputs:
- The outputs can be configured in a tri-state mode, allowing multiple devices to connect to a common bus without signal interference.

6. Input Compatibility:
- The inputs are TTL-compatible, which means they can interface directly with TTL outputs without additional buffering.

7. Wide Temperature Range:
- The IC is designed to operate within a temperature range of -40°C to +85°C, ensuring reliability in various environments.

## Specifications

Here are the detailed specifications of the CD74ACT138E:

| Parameter | Value |
|-------------------------------------|---------------------------|
| Package Type | DIP, SOIC, TSSOP |
| Supply Voltage (Vcc) | 4.5V to 5.5V |
| Input Voltage (VIH) | 2.0V (minimum) |
| Input Voltage (VIL) | 0.8V (maximum) |
| Output Voltage (VOH) | Vcc - 0.1V (minimum) |
| Output Voltage (VOL) | 0.1V (maximum) |
| Propagation Delay | 7 ns (typical at 5V) |
| Power Dissipation | 1 mW (typical) |
| Output Current | ±24 mA (maximum) |
| Logical Functionality | 3-to-8 line decoder |
| Temperature Range | -40°C to +85°C |

## Application Areas

The CD74ACT138E is utilized in various applications, including:

1. Memory Decoding: Used in microprocessor systems to decode address lines for memory selection.
2. Data Routing: Facilitates data path selection in communication systems.
3. Multiplexing: Serves as a demultiplexer for routing data from one source to multiple destinations.
4. Control Logic: Incorporates in control systems where multiple outputs are required from a limited number of inputs.

## Conclusion

The Harris Corporation CD74ACT138E is an essential component for designers and engineers working with digital circuits. Its combination of performance, low power consumption, and versatility makes it a valuable addition to a wide range of electronic applications. For more detailed information, including application circuits and design guidelines, refer to the product datasheet provided by the manufacturer.