SN74HC138PWT

Overview

The SN74HC138PWT is a single 3-to-8 decoder and demultiplexer manufactured by Texas Instruments. It operates within a supply voltage range of 2 V to 6 V and features active-low outputs. The device incorporates three enable inputs (one active-high, two active-low) to facilitate cascading or data reception applications. Designed for high-speed memory decoding and data routing, it offers low power consumption with a maximum ICC of 80 µA at 6 V. The component utilizes TSSOP-16 surface-mount packaging.

Feature Summary

• Incorporates three binary select inputs to activate one of eight normally-high outputs, pulling the selected line low.
• Features three enable pins allowing simplified expansion into larger decoders without external inverters.
• Designed for high-performance systems requiring minimal propagation delay impact on memory access times.

Applications

• LED Matrix Displays
• Server Systems
• White Goods
• Power Infrastructure

Procurement Notes

Verify the specific ordering suffix 'T' against current manufacturer documentation, as availability status may vary. Confirm package dimensions and thermal resistance values match design requirements. Ensure ESD handling precautions are followed during installation. Check for RoHS compliance details in the latest datasheet revision.

Selection Notes

Select this component when a single 3-to-8 decode function is required in a compact surface-mount form factor. Consider the TSSOP-16 package constraints regarding thermal dissipation and board space. Evaluate the operating temperature range of -40°C to +85°C against environmental conditions. Verify that the logic family compatibility meets system interface needs.

Part Context

This part belongs to the SNx4HC138 series of 3-line to 8-line decoders and demultiplexers. It shares functional characteristics with other packages in the family, such as SOIC and SSOP variants, but differs in physical footprint and mounting style. The HC logic family provides CMOS performance with TTL-compatible loading capabilities.

Replacement Considerations

SN74HC138PWR is an active production alternative in the same TSSOP-16 package. SN74HC138PW is listed as obsolete. Other package types like SN74HC138D or SN74HC138DB require PCB layout modifications due to different pinouts and dimensions.