SN74AHCT138NS

Signal Switches, Multiplexers, Decoders Overview

The SN74AHCT138NS is a 3-line to 8-line decoder and demultiplexer from the Texas Instruments 74AHCT logic family. It operates with a supply voltage range of 4.5 V to 5.5 V, ensuring compatibility with standard 5-V CMOS systems while accepting TTL-compatible inputs. The device features three address inputs (A, B, C) and eight active-low outputs (Y0–Y7). It includes three enable inputs: two active-low (G2A, G2B) and one active-high (G1), which must be in their correct states for the decoder to function. Packaged in a 16-pin DIP format, it supports surface mount or through-hole integration depending on the specific variant configuration.

Signal Switches, Multiplexers, Decoders Feature Summary

• Provides decoding functionality by converting three binary address inputs into one of eight mutually exclusive active-low outputs.
• Incorporates three independent enable inputs that allow cascading multiple units or controlling data flow within complex digital circuits.
• Features TTL-compatible input thresholds, facilitating direct interfacing between 5-V CMOS logic and legacy TTL components.

Signal Switches, Multiplexers, Decoders Applications

• Address decoding in microprocessor-based memory systems
• Data routing in multiplexed communication networks
• Control signal generation in industrial automation equipment

Signal Switches, Multiplexers, Decoders Procurement Notes

Verify the package type matches your PCB footprint requirements, as the NS suffix typically denotes a plastic dual-in-line package. Confirm the operating temperature range aligns with your environmental specifications. Ensure the logic family voltage compatibility meets your system's power supply constraints before finalizing procurement.

Signal Switches, Multiplexers, Decoders Selection Notes

Select this component when high-speed switching is required alongside robust noise immunity in 5-V applications. The AHCT series offers faster propagation delays compared to standard HC logic while maintaining TTL input compatibility. Consider the DIP packaging if prototyping or through-hole assembly is necessary for your design workflow.

Signal Switches, Multiplexers, Decoders Part Context

This part belongs to the 74AHCT logic family, designed for high-speed CMOS applications requiring TTL input compatibility. It serves as a core building block for digital logic systems needing efficient address decoding or demultiplexing capabilities within automotive and industrial environments.

Signal Switches, Multiplexers, Decoders Replacement Considerations

Compatible substitutes include the SN74AHCT138D (SOIC package) and SN74AHCT138PW (TSSOP package) for equivalent electrical performance in different form factors. For non-automotive grade requirements, the SN74AHCT138DR offers similar functionality in a reel-packaged SOIC format.