CD74HC138M

Signal Switches, Multiplexers, Decoders Overview

The CD74HC138M is a high-speed CMOS logic device functioning as a 3-to-8 line decoder and demultiplexer. Manufactured by Texas Instruments, it operates within a supply voltage range of 2 V to 6 V and supports an operating temperature range from -55 °C to +125 °C. The component utilizes a 16-pin Small Outline (SOIC) package with surface-mount technology. It features three binary address inputs and eight mutually exclusive outputs that are normally high but go low when selected. Propagation delays typically range between 7 ns and 22 ns depending on load conditions.

Signal Switches, Multiplexers, Decoders Feature Summary

• Provides three binary weighted address inputs to select one of eight mutually exclusive outputs
• Includes two active-low and one active-high enable inputs to simplify cascading applications
• Offers balanced propagation delay and transition times for efficient data routing
• Delivers output drive capability equivalent to ten Low-Power Schottky TTL loads

Signal Switches, Multiplexers, Decoders Applications

• Memory address decoding in storage systems
• Data routing and distribution networks
• I/O port selection circuits
• Demultiplexing signal paths

Signal Switches, Multiplexers, Decoders Procurement Notes

Verify the specific suffix 'M' corresponds to the SOIC-16 package variant rather than other packaging options like TSSOP or DIP. Confirm the manufacturing date code and lot traceability requirements against project specifications. Ensure the component meets RoHS compliance standards if required by the assembly process. Cross-reference the ordering part number with the manufacturer's current datasheet to validate pinout compatibility.

Signal Switches, Multiplexers, Decoders Selection Notes

Select this component when a high-speed CMOS decoder is required for memory addressing or data distribution tasks. It serves as a suitable alternative to legacy LSTTL decoders due to lower power consumption while maintaining comparable switching speeds. Consider the wide operating temperature range for industrial environments. Verify that the 2 V to 6 V supply voltage range aligns with the system's power rails before integration.

Signal Switches, Multiplexers, Decoders Part Context

This device belongs to the CD74HC138 family of high-speed silicon-gate CMOS logic components. It is functionally compatible with the HC/UH logic series and offers performance characteristics similar to Low-Power Schottky TTL. The family includes variants such as the non-inverting CD74HC238 and the HCT versions which provide direct LSTTL input compatibility. These devices are designed for applications requiring fast decoding with minimal power dissipation.

Signal Switches, Multiplexers, Decoders Replacement Considerations

The CD74HC138MG4 is a lead-free variant of this component. Other compatible parts include the SN74HC138N for through-hole applications and the SN74HCS138QDYYRQ1 for automotive-grade requirements. Verify pinout and electrical specifications before substituting with generic 74HC138 equivalents from other manufacturers.