SN74F138NE4

Overview

The SN74F138NE4 is a 3-line to 8-line decoder/demultiplexer from the Texas Instruments SN74F series. It operates within a supply voltage range of 4.5 V to 5.5 V and features an operating temperature range of 0°C to 70°C. The device utilizes a 16-pin Plastic Dual In-Line Package (PDIP). Electrical characteristics include a low-level output current of 20 mA and a high-level output current of -1 mA at VCC = 4.5 V. Switching performance under standard test conditions (VCC = 5 V, CL = 50 pF) specifies propagation delays with maximum values of 8.5 ns for A/B/C-to-Y transitions and 9 ns for enable input-to-output transitions.

Feature Summary

• Incorporates three enable inputs (one active-high and two active-low) to simplify cascading and data reception applications without requiring external inverters.
• Designed specifically for high-speed memory decoding and data routing systems where minimizing system decoding delay is critical.
• Provides eight active-low outputs selected by three binary-select inputs to facilitate precise address decoding.

Applications

• High-performance memory decoding systems
• Data transmission and routing applications
• Expansion of decoder systems to implement larger line decoders

Procurement Notes

Verify that the ordering suffix 'E4' corresponds to the specific lead-free PDIP package configuration as documented in the manufacturer's packaging addendum. Confirm that the component meets the required commercial temperature specifications for the intended operational environment before finalizing procurement.

Selection Notes

Select this component when short propagation delays are required for memory addressing or data routing tasks. Ensure the design accommodates the specific logic levels and current drive capabilities defined in the electrical characteristics table. Verify compatibility with the target PCB layout constraints associated with the 16-pin DIP form factor.

Part Context

This device belongs to the SN74F family of high-speed TTL logic components. It serves as a functional equivalent to the military-grade SN54F138, distinguished primarily by its extended commercial temperature rating. The part is designed to integrate directly into digital logic circuits requiring efficient binary-to-decimal translation.

Replacement Considerations

SN74F138N

FAQ

How many enable inputs does the SN74F138NE4 possess?

The device incorporates three enable inputs: one active-high (G1) and two active-low (G2A and G2B).

What is the function of the enable inputs regarding system expansion?

The enable inputs allow for the implementation of larger decoders, such as a 24-line decoder, without the need for external inverters.