74VHCT138ASJ

Signal Switches, Multiplexers, Decoders Overview

The Fairchild Semiconductor 74VHCT138ASJ is a high-speed silicon-gate CMOS decoder/demultiplexer belonging to the 74VHCT logic family. It features three binary address inputs and eight active-low outputs, enabling one of the outputs to be selected based on the input code when enabled. The device operates within a supply voltage range of 4.5 V to 5.5 V and utilizes a 16-pin SOP package. Designed for low power consumption while maintaining speed comparable to Low-Power Schottky TTL, it includes three enable inputs to facilitate cascading applications in memory addressing or data routing systems.

Signal Switches, Multiplexers, Decoders Feature Summary

• Provides 3-to-8 line decoding functionality with active-low outputs
• Features three enable inputs to support cascaded configurations
• Operates at speeds comparable to Low-Power Schottky TTL with CMOS low power characteristics

Signal Switches, Multiplexers, Decoders Applications

• Memory address decoding
• Data routing
• Demultiplexing

Signal Switches, Multiplexers, Decoders Procurement Notes

Verify the manufacturer designation as Fairchild Semiconductor, noting that Fairchild was acquired by onsemi. Confirm the specific suffix 'SJ' corresponds to the 16-pin SOP package and check current availability status, as legacy components may have limited stock or obsolescence notices. Ensure compatibility with 5 V logic levels required by the VHCT series.

Signal Switches, Multiplexers, Decoders Selection Notes

Select this component when a 3-to-8 decoder with active-low outputs is required in a 5 V system. The VHCT series ensures TTL-compatible input thresholds while offering CMOS power efficiency. Verify that the SOP-16 package fits the PCB layout constraints and that the operating temperature range meets the application requirements.

Signal Switches, Multiplexers, Decoders Part Context

This part belongs to the 74VHCT family of high-speed CMOS logic devices. The VHCT series is characterized by its ability to interface directly with TTL logic families due to compatible input voltage thresholds. The 138 variant specifically implements the standard 3-to-8 decoder function widely used in digital control circuits.

Signal Switches, Multiplexers, Decoders Replacement Considerations

Compatible replacements include the onsemi MC74VHCT138ASJ and other manufacturers' equivalents such as the TC74VHCT138AFK from Toshiba, provided they match the 16-pin SOP package and electrical specifications.