SN74HCT138ANS

Overview

The SN74HCT138ANS is a single 3-line to 8-line decoder/demultiplexer manufactured by Texas Instruments. It belongs to the HCT logic series, utilizing high-speed silicon gate CMOS technology with TTL-compatible inputs. The device features three binary address inputs (A0, A1, A2) and eight active-low outputs. It includes three enable inputs: two active-low (E1, E2) and one active-high (E3), facilitating cascading applications. The component operates within a supply voltage range of 4.5 V to 5.5 V and supports surface-mount installation in a TSSOP-16 package.

Feature Summary

• TTL-compatible input levels ensure seamless integration with standard logic families
• Active-low outputs provide direct interfacing for memory addressing and data routing
• Multiple enable inputs allow efficient expansion through cascaded configurations

Applications

• Memory address decoding systems
• Data routing and distribution networks
• Industrial control logic circuits

Procurement Notes

Verify the specific suffix 'ANS' against official manufacturer documentation to confirm pinout compatibility and electrical specifications. Ensure the selected variant matches the required TSSOP-16 package dimensions and thermal characteristics for your design constraints.

Selection Notes

Select this component when TTL-compatible CMOS performance is required at 5V operation. Consider the HCT series for noise immunity and speed advantages over standard HC logic while maintaining backward compatibility with existing TTL designs.

Part Context

This part is part of the widely adopted 74HC/HCT family of logic ICs. It serves as a fundamental building block for digital systems requiring signal demultiplexing or address decoding functions within constrained space environments typical of modern electronic assemblies.

Replacement Considerations

Compatible substitutes include SN74HCT138DR and SN74HCT138PWR from Texas Instruments, provided the package type difference is accommodated in the PCB layout.