CD74HCT139E

Overview

The CD74HCT139E is a dual 2-to-4 line decoder/demultiplexer manufactured by Harris Corporation. It belongs to the HCT series of high-speed CMOS logic devices, designed for operation with standard TTL-compatible inputs. The component integrates two independent decoding circuits within a single package, allowing for efficient address decoding or data distribution in digital systems. It features inverted outputs and is available in a 16-pin Dual In-Line Package (DIP).

Feature Summary

• Integrates two independent 2-to-4 line decoders within a single integrated circuit.
• Features inverted outputs suitable for active-low addressing applications.
• Utilizes HCT CMOS technology for compatibility with standard TTL logic levels.

Applications

• Address decoding in microprocessor-based memory systems.
• Data distribution in digital control circuits.
• Demultiplexing signals in communication interfaces.

Procurement Notes

Verify the manufacturer origin carefully, as Texas Instruments acquired Harris Semiconductor's logic assets. Ensure the specific part number corresponds to Harris production if that is a strict requirement, noting that equivalent TI versions may be functionally identical but carry different branding. Confirm RoHS compliance status as older Harris parts may not meet current environmental standards.

Selection Notes

Select this component when a dual decoder configuration is required to save board space. The HCT series ensures compatibility with 5V TTL logic families. Consider the 16-pin DIP package for through-hole prototyping or legacy socketed designs. Verify input voltage thresholds match the system's logic levels before implementation.

Part Context

This device is part of the broader 74HCT logic family, which bridges the performance gap between standard HC CMOS and older TTL technologies. Harris Corporation was a significant producer of these logic ICs before its semiconductor division was acquired by Texas Instruments. The CD74 prefix indicates commercial grade temperature range and specific packaging variations.