SN74ALS138AD

Signal Switches, Multiplexers, Decoders Overview

The SN74ALS138AD is a high-speed ALS logic decoder/demultiplexer manufactured by Texas Instruments. It features three address inputs and eight active-low outputs, enabling the selection of one of eight output lines based on binary input codes. The device operates within a supply voltage range of 4.5 V to 5.5 V and includes two active-low and one active-high enable inputs for system expansion. Packaged in a 16-pin SOIC (N) surface-mount format, it offers a propagation delay of 22 ns and supports through-hole or surface-mount installation with an operating temperature range from 0°C to +70°C.

Signal Switches, Multiplexers, Decoders Feature Summary

• Provides decoding and demultiplexing functions using three binary address inputs to select one of eight active-low outputs.
• Includes dual active-low and single active-high enable inputs to facilitate cascading and complex system control.
• Utilizes Schottky-clamped bipolar technology to ensure high switching speeds and reduced power consumption.

Signal Switches, Multiplexers, Decoders Applications

• Address decoding in microprocessor-based systems
• Demultiplexing data streams in digital communication circuits
• Memory chip select generation in computer architectures

Signal Switches, Multiplexers, Decoders Procurement Notes

Verify the specific package suffix 'AD' corresponds to the SOIC-16 variant when sourcing. Confirm RoHS compliance status as manufacturing standards may evolve. Check for end-of-life notifications or obsolescence notices from Texas Instruments prior to finalizing procurement plans to ensure long-term availability.

Signal Switches, Multiplexers, Decoders Selection Notes

Select this component when a fast, low-power 3-to-8 line decoder is required in a surface-mount design. Ensure the application voltage remains strictly between 4.5 V and 5.5 V. Verify that the load requirements on the active-low outputs are compatible with the standard ALS drive capabilities.

Signal Switches, Multiplexers, Decoders Part Context

This part belongs to the Texas Instruments SN74ALS series, which represents Advanced Low-Power Schottky logic. This family bridges the performance gap between standard TTL and faster ECL technologies, offering significantly improved speed while maintaining lower power dissipation than conventional LS logic families.

Signal Switches, Multiplexers, Decoders Replacement Considerations

Compatible substitutes include the SN74ALS138AN for through-hole applications or other SN74ALS138 variants with different packaging suffixes. Cross-reference with equivalent parts from other manufacturers such as ON Semiconductor or NXP, ensuring pinout and electrical specifications match exactly.