74HC138 Integrated Circuit Decoder-Demultiplexer DIP-16

The 74HC138 is a high-speed Si-gate CMOS 3-to-8 line decoder/demultiplexer designed for applications that demand minimal propagation delay, such as memory decoding, data routing, and chip-select logic. With active-LOW outputs and flexible enable control, it’s ideal for both electronics engineers and hobbyists building logic systems and microcontroller-based projects with Arduino, Raspberry Pi, and other development boards.

Key Features ⚙️

• Three binary select inputs: A, B, C
• Three enable inputs for flexible control and easy cascading: E1 (active HIGH), E2 and E3 (active LOW)
• Eight mutually exclusive outputs (Y0–Y7) with active-LOW logic
• Demultiplexing functionality for routing one input to multiple outputs
• Multiple enable inputs support straightforward expansion to larger decode widths
• Engineered for low propagation delay in high-performance digital systems
• DIP-16 package — breadboard-friendly and easy to integrate into prototypes

Technical Specifications 🔧

• Operating Voltage: 2.0 V to 6.0 V
• Operating Temperature: -40°C to +125°C
• Logic Family: 74HC (CMOS, high-speed)
• Package Type: DIP-16

Typical Applications 🧰

• Memory decoding and address decoding
• Data routing and signal demultiplexing
• Chip-select generation for ROM/RAM/peripherals
• Computing systems and digital logic design
• Telecommunications and industrial control systems
• GPIO expansion, LED matrix/segment driving, and scanning with Arduino and Raspberry Pi

Integration Notes 💡

• Outputs are active-LOW; interface directly with devices expecting low-true enables or use pull-ups for logic-level translation.
• Use the three enable pins to cascade multiple 74HC138 devices for decoding more than 3 address lines.
• For Raspberry Pi (3.3 V logic), power the 74HC138 at 3.3 V for direct compatibility, or use level shifting if the IC is at 5 V. Note: at 5 V supply, VIH may exceed 3.3 V.
• Works well in Arduino projects as a compact way to convert 3 control lines into eight low-true outputs for modules and electronics components.

Why Choose the 74HC138? ✅

• High-speed CMOS performance for timing-critical designs
• Simple interface with common microcontrollers and development boards
• Reliable decoding with mutually exclusive outputs to prevent bus contention

Package Contents 📦

• 1 × 74HC138 Decoder/Demultiplexer IC (DIP-16)

Optimize your digital designs with the 74HC138 — a robust, easy-to-use logic IC for Arduino, Raspberry Pi, and microcontroller applications requiring precise voltage-level decoding and reliable demultiplexing.