SN74HC139NS

Overview

The SN74HC139NS is a dual 2-line to 4-line decoder/demultiplexer from the Texas Instruments HC logic family, housed in a 16-pin Small Outline (SO) package. It operates within a supply voltage range of 2 V to 6 V and supports an operating temperature range of -40°C to +85°C. The device features fully buffered inputs and active-low outputs. Key electrical characteristics include a typical propagation delay of 10 ns at 5 V, low power consumption with a maximum ICC of 80 μA, and output drive capabilities of ±4 mA at 5 V.

Feature Summary

• Designed for high-speed memory decoding and data-transmission systems
• Incorporates two enable inputs to simplify cascading and data reception
• Features fully buffered inputs representing only one normalized load

Applications

• High-performance memory system decoding
• Data-routing applications requiring short propagation delays
• Demultiplexing circuits utilizing active-low strobe inputs

Procurement Notes

Verify the specific ordering suffix 'NS' corresponds to the 16-pin SO package variant. Confirm RoHS compliance status and lead finish details via the manufacturer's current orderable addendum. Ensure thermal management aligns with the junction-to-ambient resistance specifications for the selected package type during design integration.

Selection Notes

Select this component when a dual 2-to-4 decoder configuration is required in a surface-mount form factor. The HC series offers compatibility with standard CMOS logic levels while providing sufficient drive strength for LSTTL loads. Consider the NS package dimensions against available PCB real estate compared to alternative packages like PDIP or TSSOP.

Part Context

This device belongs to the SNx4HC139 family, which includes variants such as SN74HC139N (PDIP), SN74HC139D (SOIC), and SN74HC139PW (TSSOP). All variants share identical internal logic functionality but differ in physical packaging, pin pitch, and thermal characteristics. The SN74HC139NS specifically utilizes the SO outline for surface-mount assembly.

Replacement Considerations

SN74HC139N

FAQ

Can the enable input be used as a data line?

Yes, the active-low enable (G) input can function as a data line in demultiplexing applications.

What is the maximum output drive capability?

The outputs can drive up to 10 LSTTL loads, with a typical drive of ±4 mA at 5 V.