SN74LVC138ADRG4

Overview

The SN74LVC138ADRG4 is a low-voltage CMOS 3-line to 8-line decoder/demultiplexer manufactured by Texas Instruments. It operates within a supply voltage range of 1.65 V to 3.6 V and features three binary address inputs and eight active-low outputs. The device includes two active-low enable inputs and one active-high enable input for expansion capabilities. Packaged in a 16-pin TSSOP, it exhibits a propagation delay of 6.7 ns at 3.0 V. The component supports surface-mount installation and functions reliably across an operating temperature range from -40°C to +85°C.

Feature Summary

• Provides decoding or demultiplexing functionality with three binary address lines controlling eight distinct active-low outputs.
• Incorporates dual active-low and single active-high enable inputs to facilitate system expansion and output control.
• Operates on low supply voltages ranging from 1.65 V to 3.6 V, ensuring compatibility with modern low-power digital systems.

Applications

• Address decoding for memory and I/O port selection in embedded systems
• Demultiplexing data streams in communication interfaces
• Control logic for peripheral device activation

Procurement Notes

Verify the specific suffix 'G4' indicates lead-free composition and RoHS compliance as per manufacturer standards. Confirm the package type matches the required PCB footprint, specifically the 16-lead Thin Shrink Small Outline Package (TSSOP). Ensure the ordering quantity aligns with reel specifications provided by authorized distributors to avoid packaging discrepancies during assembly.

Selection Notes

Select this component when low power consumption and wide voltage tolerance are required for logic decoding tasks. The LVC series offers superior performance compared to older LV variants while maintaining pin compatibility. Consider the propagation delay characteristics relative to system clock speeds. Verify that the active-low output polarity aligns with downstream circuit requirements without additional inversion stages.

Part Context

This part belongs to the SN74LVC138A family of decoders and demultiplexers. It serves as a standard logic IC for converting binary codes into one-of-eight active signals. The device is widely used in digital electronics where efficient address mapping and signal routing are necessary. It complements other logic families by providing high-speed operation at reduced voltage levels.

Replacement Considerations

SN74LVC138ADRE4: Equivalent function with different tape-and-reel packaging configuration.

FAQ

What is the logic state of the outputs when enabled?

The outputs are active-low, meaning they drive a low logic level when selected and remain high otherwise.

How many enable inputs does the device have?

It has three enable inputs: two active-low (G1, G2A, G2B) and one active-high (G1), allowing for cascading multiple units.