MM74HCT138MX 3-to-8 Line Decoder IC – SOIC-16

Description

The MM74HCT138MX is a high-performance 3-to-8 line decoder designed using advanced silicon-gate CMOS technology. It is specifically engineered for efficient memory address decoding and high-speed data routing applications. By combining the low power consumption and high noise immunity of CMOS with the high-speed characteristics of low-power Schottky TTL (LSTTL), this IC serves as a versatile interface component between TTL, NMOS, and CMOS logic families.

The device features three binary select inputs (A, B, and C) that determine which of the eight output lines will be driven LOW, provided the device is enabled. It includes a flexible enable structure—consisting of two active-LOW and one active-HIGH inputs (G1, G2A, G2B)—which allows for easy cascading of multiple decoders to expand the addressable range.

Note: Product images are for illustrative purposes only. For detailed timing diagrams, input/output voltage levels, and PCB layout recommendations to maintain signal integrity, please refer to the official ON Semiconductor datasheet.

Features

• High Compatibility: Functionally and pin-compatible with the industry-standard 74LS138.
• Efficient Logic: Capable of driving 10 LSTTL equivalent loads, making it ideal for system-level integration.
• Flexible Enable Structure: Includes three enable inputs (G1, G2A, G2B) to simplify cascading and expansion.
• ESD Protection: All inputs are protected against electrostatic discharge via internal diodes to VCC and Ground.
• Low Power: Consumes significantly less power than traditional TTL-based decoders.
• Wide Temp Range: Operates reliably from -40°C to +85°C.

Benefits

• Plug-in Replacement: An excellent drop-in upgrade for existing 74LS138 designs to reduce system power consumption.
• Seamless Interfacing: Specifically designed to act as a bridge between different logic families (TTL, CMOS, NMOS).
• System Reliability: High noise immunity and robust input protection ensure consistent operation in complex electronic environments.

Applications

• Memory Address Decoding: Selecting specific memory banks in microcontroller-based systems.
• Data Routing: Directing signals to various peripherals or registers.
• Multiplexing: Used in complex digital logic circuits to select one of many signals.
• Chip Select Decoding: Managing multiple ICs on a shared communication bus.

Package Includes

• 1 x MM74HCT138MX 3-to-8 Line Decoder IC (SMD-16)

Specifications