MC74AC138DT

Overview

The MC74AC138DT is a high-speed CMOS 3-to-8 line decoder/demultiplexer manufactured by onsemi, formerly Motorola. It operates within a supply voltage range of 2V to 6V and features low input leakage current. The device utilizes a TSSOP-16 surface-mount package and supports an operating temperature range from -40°C to +85°C. It includes three address inputs and eight active-low outputs with three enable inputs for flexible system integration.

Feature Summary

• High-speed CMOS technology ensures fast switching performance with low power consumption.
• Active-low outputs provide direct interfacing capabilities for various digital logic systems.
• Three enable inputs allow precise control over device activation and system synchronization.

Applications

• Memory address decoding in embedded systems
• Signal routing in data acquisition circuits
• Industrial control logic interfaces

Procurement Notes

Verify the manufacturer designation carefully, as onsemi acquired Motorola's semiconductor business. Confirm the specific suffix indicates the TSSOP-16 package variant. Ensure compliance with RoHS directives if required by your application standards. Cross-reference part numbers with official distributor catalogs to confirm availability and authenticity before procurement.

Selection Notes

Select this component when a 3-to-8 decoding function is required in space-constrained designs. The TSSOP-16 package offers a compact footprint suitable for dense PCB layouts. Consider the 2V to 6V operating range for compatibility with varying logic levels. Verify that the active-low output polarity aligns with downstream circuit requirements.

Part Context

This component belongs to the 74AC logic family, known for superior speed compared to standard 74LS series devices. The AC series maintains pin compatibility with legacy designs while offering improved performance characteristics. It serves as a foundational building block for complex digital systems requiring reliable signal distribution and address decoding functions.

Replacement Considerations

Compatible substitutes include the MC74AC138DTR2G and 74AC138SC. These alternatives share identical logical functionality but may differ in packaging or reel specifications. Verify electrical parameters and pinout compatibility before substitution to ensure seamless integration into existing designs.