74AC139SCX

Overview

The Fairchild Semiconductor 74AC139SCX is a dual 2-line-to-4-line decoder/demultiplexer from the 74AC logic series. It features two independent decoders, each with two address inputs and four active-low outputs. The device operates within a supply voltage range of 2 V to 6 V and supports surface-mount installation in an SOIC-16 package. It functions reliably across an industrial temperature range of -40 °C to +85 °C.

Feature Summary

• Contains two independent 2-to-4 line decoders or demultiplexers
• Provides active-low outputs for signal selection
• Supports high-speed CMOS operation with low power consumption

Applications

• Address decoding in microprocessor systems
• Data routing and demultiplexing applications
• Memory chip select generation

Procurement Notes

Verify the manufacturer designation on the component marking against official Fairchild Semiconductor documentation. Confirm that the SOIC-16 package dimensions and pinout match the specific datasheet revision. Ensure compliance with RoHS directives if required by the application environment. Cross-reference the part number suffix to confirm lead-free status and packaging type.

Selection Notes

Select this component when dual independent decoding channels are required in a compact surface-mount form factor. The AC series offers higher speed performance compared to standard LS logic while maintaining CMOS power efficiency. Verify that the operating voltage range aligns with the system's power supply rails and that the output drive capability meets the load requirements.

Part Context

This component belongs to the 74AC family of high-speed CMOS logic devices. It serves as a functional equivalent to other industry-standard dual decoders but is specifically manufactured under the Fairchild Semiconductor brand. The device integrates two complete decoding circuits into a single 16-pin package, optimizing board space for complex digital logic designs.