SN74F138DB

Overview

The SN74F138DB is a high-speed silicon-gate CMOS decoder/demultiplexer manufactured by Texas Instruments. It features a 16-pin SOIC surface-mount package and operates within a supply voltage range of 4.5 V to 5.5 V. The device functions as a 3-to-8 line decoder with active-low outputs, designed for low power dissipation and compatibility with standard TTL logic levels. It supports an operating temperature range from 0°C to +70°C.

Feature Summary

• High-speed silicon-gate CMOS technology ensures low power consumption while maintaining fast switching speeds.
• Active-low decoding capability allows direct interfacing with memory address decoders and control circuits.
• Three enable inputs provide flexible cascading options for expanding system capacity without additional gating.

Applications

• Memory address decoding in computer systems
• Control signal routing in industrial automation
• Data distribution in telecommunications equipment

Procurement Notes

Verify the specific suffix 'D' confirms the SOIC-16 package variant. Confirm the absence of automotive or extended temperature qualifiers if standard commercial grade is required. Ensure the ordering part number matches the exact revision level needed for your PCB footprint and design specifications.

Selection Notes

Select this component when a balance of speed and power efficiency is required for 5V logic applications. Consider the SN74HC138 for lower voltage operation or the SN74LS138 for legacy pin-compatible replacement with slower performance but higher drive current capabilities.

Part Context

This part belongs to the Texas Instruments SN74F series, which utilizes advanced FET technology for improved performance over older transistor-transistor logic families. The 138 designation specifically identifies it as a 3-line to 8-line decoder within the broader logic IC portfolio.

Replacement Considerations

SN74F138DR (Reel version), SN74F138N (Through-hole DIP), SN74HC138D (HC Series equivalent).