SN74ALS139N

Overview

The SN74ALS139N is a dual 2-line to 4-line decoder/demultiplexer manufactured by Texas Instruments. It belongs to the ALS (Advanced Low-power Schottky) logic family and operates within a supply voltage range of 4.5 V to 5.5 V. The device features two independent decoders, each with two address inputs and four active-low outputs. Each decoder includes an active-low enable input for control. The component is housed in a standard 16-pin PDIP package designed for through-hole mounting.

Feature Summary

• Dual independent 2-to-4 line decoding capability
• Active-low outputs for direct interfacing
• Active-low enable inputs for selective operation

Applications

• Address decoding in microprocessor systems
• Data distribution in digital circuits
• Memory chip select generation

Procurement Notes

Verify the specific suffix 'N' corresponds to the PDIP package variant when sourcing. Confirm the manufacturer is Texas Instruments to ensure compatibility with ALS logic specifications. Check RoHS compliance status as required by project regulations. Ensure the supplier provides official datasheets for technical validation before integration.

Selection Notes

Select this component for applications requiring dual independent decoding channels within a single package. The ALS series offers improved speed over standard TTL while maintaining low power consumption. Consider the PDIP package constraints if surface mount alternatives are not feasible. Verify that active-low output polarity aligns with downstream circuit requirements.

Part Context

This part is part of the SN74ALS139 family, which includes variants with different packaging options such as SOIC or TSSOP. The 'N' suffix specifically denotes the plastic DIP package. It serves as a functional equivalent to other industry-standard 2-to-4 decoders but is optimized for the ALS performance profile.

Replacement Considerations

Cross-reference with SN74ALS139J or SN74ALS139D for alternative package types from Texas Instruments. Verify pinout compatibility with third-party equivalents like the 74LS139, noting potential differences in switching speeds and power dissipation characteristics.