CD74HC238M

Overview

The CD74HC238M is a high-speed CMOS logic device manufactured by Harris Corporation, functioning as a 3-to-8 line decoder and demultiplexer. It features three binary address inputs (A0, A1, A2) and eight mutually exclusive outputs that transition to a high state when enabled. The component includes two active-low enable inputs and one active-high enable input to facilitate cascading configurations. Designed for surface-mount applications, it utilizes a 16-pin Small Outline Integrated Circuit (SOIC) package with plastic construction.

Feature Summary

• Provides eight mutually exclusive outputs that switch to a high state upon activation
• Includes composite enable inputs to simplify cascading without external logic gates
• Compatible with standard SOIC surface-mount packaging for automated assembly

Applications

• Memory address decoding in digital systems
• Data routing and signal distribution
• Peripheral device selection interfaces

Procurement Notes

Verify the manufacturer designation on the component marking, as this part was produced by Harris Corporation before its semiconductor division was acquired. Confirm the specific suffix matches the original Harris specification rather than subsequent Texas Instruments production runs. Ensure the package dimensions align with the legacy PDSO16 format documented in historical datasheets.

Selection Notes

Select this component when a non-inverting 3-to-8 decoder is required within a CMOS logic family. It serves as an alternative to the HC138 series, which provides low-active outputs instead of high-active ones. Consider the availability of vintage manufacturing sources versus modern equivalents from successor manufacturers.

Part Context

This device belongs to the 74HCT/HC logic family, characterized by high-speed silicon gate CMOS technology. It offers performance comparable to low-power Schottky TTL while maintaining typical CMOS power advantages. The component is part of a broader lineage of decoders used extensively in computing and industrial control hardware.

Replacement Considerations

CD74HC238M96