MC74AC138M

Overview

The MC74AC138M is a high-speed CMOS decoder/demultiplexer manufactured by onsemi. It features three address inputs and eight active-low outputs, housed in a 16-pin SOIC package. The device operates within a supply voltage range of 2 V to 6 V and supports surface-mount installation. It functions as a single circuit with inverted outputs, designed for industrial temperature ranges from -40°C to +85°C.

Feature Summary

• Provides one-of-eight decoding or demultiplexing functionality using three binary address lines.
• Features active-low outputs suitable for direct interfacing with logic circuits requiring low-state activation.
• Utilizes CMOS technology to ensure high noise immunity and low power consumption across the operating voltage range.

Applications

• Address decoding in microprocessor-based systems
• Data distribution in digital communication interfaces
• Memory chip selection in embedded storage architectures

Procurement Notes

Verify the specific suffix 'M' against the official datasheet to confirm the SOIC-16 package variant. Confirm RoHS compliance status through current environmental declarations. Check for obsolescence notices or lifecycle changes directly from onsemi documentation before finalizing procurement plans.

Selection Notes

Select this component when a 2V to 6V operating range is required, distinguishing it from standard 5V-only AC series parts. Ensure the design accommodates the 16-SOIC footprint and surface-mount assembly constraints. Verify that the active-low output polarity aligns with the target system logic requirements.

Part Context

This part belongs to the 74AC logic family, offering faster switching speeds than standard 74LS counterparts while maintaining CMOS power efficiency. The MC74 prefix indicates manufacturing by Motorola (now onsemi), ensuring compatibility with legacy designs originally specified under the Motorola naming convention.

Replacement Considerations

Direct substitutes include the 74AC138SC and MC74AC138DG. Verify pinout compatibility and electrical specifications against the original datasheet before substitution.