74AC139SJX

Overview

The Fairchild Semiconductor 74AC139SJX is a dual 2-line-to-4-line decoder/demultiplexer from the AC series. It operates with a supply voltage range of 2V to 6V and features inverted outputs. The device is housed in a 16-lead Small Outline Package (SOP) with a maximum propagation delay of 10.5 ns at 5V with a 50 pF load. It supports an operating temperature range from -40°C to 85°C.

Feature Summary

• Dual independent 2-to-4 line decoding or demultiplexing functionality within a single package
• CMOS construction providing low power consumption and high noise immunity
• Inverted output polarity for direct interface compatibility with active-low logic inputs

Applications

• Address decoding for memory and I/O port selection in embedded systems
• Demultiplexing data streams to multiple peripheral devices
• Control signal distribution in industrial automation controllers

Procurement Notes

Verify the specific suffix 'SJX' against the manufacturer's official ordering guide, as it denotes the SOP-16 package and tape-and-reel packaging configuration. Confirm that the component meets current RoHS directives and environmental compliance standards required for your assembly process. Ensure the supplier provides traceability documentation consistent with Fairchild Semiconductor (now onsemi) quality protocols.

Selection Notes

Select this component when dual independent decoding channels are required in a compact surface-mount footprint. The AC series offers faster switching speeds compared to standard HC variants while maintaining CMOS power efficiency. Verify that the 2V to 6V supply range aligns with your system's voltage rails and that the 10.5 ns propagation delay meets your timing constraints.

Part Context

This part belongs to the 74AC family of high-speed CMOS logic devices. It is functionally compatible with other 74AC139 variants but differs in package type and reel specifications. The device serves as a core logic element for address decoding applications where space savings and speed are prioritized over legacy TTL performance levels.