MC74ACT138N

Overview

The MC74ACT138N is a high-speed 1-of-8 decoder/demultiplexer manufactured by onsemi. It accepts three binary weighted address inputs (A0, A1, A2) and provides eight mutually exclusive active-LOW outputs (O0-O7). The device operates within a supply voltage range of 4.5 V to 5.5 V. It features TTL-compatible inputs and includes three enable inputs: two active-LOW (E1, E2) and one active-HIGH (E3). Outputs can source or sink up to 24 mA. The component is housed in a 16-lead PDIP package.

Feature Summary

• Features multiple input enables for easy parallel expansion to larger decoders
• Provides active-low mutually exclusive outputs
• Outputs capable of sourcing and sinking 24 mA
• Includes TTL compatible inputs

Applications

• High-speed bipolar memory chip select address decoding
• Parallel expansion to 1-of-24 or 1-of-32 decoders
• Demultiplexing applications using enable inputs as data/strobe signals

Procurement Notes

Verify the specific ordering suffix 'N' corresponds to the PDIP-16 package configuration. Confirm RoHS compliance status through official documentation as specifications apply to both standard and Pb-free devices. Ensure the required operating temperature range aligns with your application environment before procurement.

Selection Notes

Select this part when TTL-compatible logic levels are required alongside AC speed performance. Verify that the 4.5 V to 5.5 V supply voltage range matches the system power rails. Consider the PDIP-16 package constraints if surface mount alternatives like SOIC or TSSOP are preferred for the design.

Part Context

This component belongs to the MC74AC/ACT138 family of 1-of-8 decoders and demultiplexers. It shares functional similarities with the MC74AC138 but distinguishes itself through TTL-compatible input thresholds. The family supports various packaging options including SOIC, TSSOP, and EIAJ formats.

Replacement Considerations

MC74AC138N serves as a non-TTL compatible alternative within the same package. MC74ACT138D offers the same logic function in an SOIC-16 package.