SN74HC138DE4

Overview

The SN74HC138DE4 is a single 3-to-8 decoder/demultiplexer from the Texas Instruments SN74HC138 family. It operates within a supply voltage range of 2 V to 6 V and features active-low outputs selected by three binary inputs (A, B, C). The device incorporates three enable inputs (one active-high G1, two active-low G2A/G2B) to facilitate cascading or demultiplexing without external logic. Designed for high-speed memory decoding and data routing, it offers low power consumption with a maximum ICC of 80 µA at 6 V.

Feature Summary

• Three binary select inputs control eight active-low outputs
• Three enable inputs simplify system expansion and data reception
• Low power consumption suitable for battery-operated applications
• Outputs can drive up to ten LSTTL loads

Applications

• High-speed memory decoders
• Data-transmission systems
• LED matrix displays
• Servers and white goods

Procurement Notes

Verify the 'E4' suffix indicates lead-free manufacturing compliant with RoHS standards. Confirm package dimensions match the SOIC-16 specification. Check current production status as some variants in this series may be obsolete. Ensure ESD precautions are followed during handling.

Selection Notes

Select this component when a 3-to-8 decoding function is required with minimal propagation delay. Verify that the operating voltage falls between 2 V and 6 V. Consider the three enable pins for complex system expansion needs. Compare thermal resistance values against PCB layout constraints.

Part Context

This part belongs to the SNx4HC138 family of 3-line to 8-line decoders and demultiplexers manufactured by Texas Instruments. The family includes various packages such as SOIC, SSOP, PDIP, and TSSOP. The HC logic series provides balanced output drive and wide operating voltage ranges compared to older logic families.

Replacement Considerations

SN74HC138DR

FAQ

How many enable inputs does the SN74HC138DE4 have?

It has three enable inputs: one active-high (G1) and two active-low (G2A and G2B).

What is the state of unselected outputs?

Unselected outputs remain in a HIGH state while the selected output is pulled LOW.