74HC138 (3 to 8 Line Decoder )

Overview

The 74HC138 is a high-speed 3-to-8 line decoder/demultiplexer from the 74HC family. It takes a 3-bit binary address input and activates one of eight outputs (active LOW) corresponding to the binary value. This IC is essential for address decoding in microcontrollers, memory expansion, and multiplexing applications. With its multiple enable inputs, it can be easily cascaded to create larger decoders, making it a versatile component for digital logic design.

Key Features

• 3-to-8 line decoding: Converts a 3-bit binary input into one of eight active-LOW outputs.
• Multiple enable inputs: Three enable pins (E1, E2, E3) allow easy expansion and control.
• High-speed operation: Propagation delay typically 12ns at 5V, ideal for high-frequency applications.
• Wide operating voltage: 2V to 6V, compatible with TTL, CMOS, and 5V microcontrollers.
• Low power consumption: CMOS technology ensures minimal power usage.
• Standard pinout: Easy to use in breadboards and PCBs, compatible with other 74-series ICs.

Technical Specifications

• Family: 74HC (High-Speed CMOS)
• Function: 3-to-8 line decoder/demultiplexer
• Supply Voltage (VCC): 2.0V to 6.0V
• Input Voltage (VI): 0V to VCC
• Output Current (IO): ±4mA (at 5V)
• Propagation Delay (tpd): 12ns (typ) at 5V, CL=50pF
• Operating Temperature: -40°C to +85°C
• Package: DIP-16 / SOIC-16
• Logic Output: Active LOW

Applications & Use Cases

• Address decoding: Expand memory or I/O in microcontroller projects (e.g., select among multiple external devices).
• Data routing: Demultiplex data lines to multiple outputs.
• LED matrix control: Select rows or columns in LED displays.
• Multiplexing: Combine with multiplexers to save I/O pins.
• Digital logic education: Teach binary decoding and combinational logic.
• Robotics: Control multiple sensors or actuators with fewer pins.

What's Included

• 1x 74HC138 IC (DIP-16 package)

Compatibility

• Works with 5V and 3.3V logic systems.
• Compatible with Arduino, Raspberry Pi, ESP32, and other microcontrollers.
• Can be cascaded to create 4-to-16 or larger decoders.
• Pin-compatible with standard 74LS138 (TTL version).

MOKWN Recommendation

For Egyptian electronics enthusiasts, the 74HC138 is a must-have for any digital logic project. Whether you're a student learning combinational logic or an engineer designing a complex system, this decoder simplifies address expansion and reduces wiring. Its low cost and wide availability make it a staple in our store. Pair it with our jumper wires and breadboards for immediate prototyping. Order now and elevate your circuit designs!