SN74HC138ADB

Overview

The SN74HC138ADB is a single 3-to-8 line decoder/demultiplexer from the Texas Instruments SN74HC138 series. It operates within a supply voltage range of 2 V to 6 V and features three binary address inputs and eight active-low outputs. The device includes three enable inputs, consisting of two low-active and one high-active terminal, which facilitate system expansion without external logic gates. Designed for surface-mount applications, it utilizes a 16-pin TSSOP package with a maximum propagation delay of 45 ns. The component supports an operating temperature range from -40°C to +85°C and complies with RoHS standards.

Feature Summary

• Integrates three enable inputs to simplify cascading and reduce external gate requirements
• Provides active-low decoded outputs for direct interface with memory or control systems
• Supports demultiplexer functionality by utilizing enable inputs as data inputs

Applications

• High-performance memory decoding in storage systems
• Data routing and transmission systems
• Industrial control logic circuits

Procurement Notes

Verify the specific suffix 'ADB' against the official Texas Instruments datasheet to confirm the exact package type and tape-and-reel specifications. Confirm current production status, as variants within this family may have different lifecycle statuses. Ensure compatibility with existing PCB footprints for the 16-pin TSSOP configuration before procurement.

Selection Notes

Select this component when a CMOS-compatible 3-to-8 decoder is required for low-power applications. The HC series offers wide voltage operation suitable for mixed-voltage systems. Verify that the 45 ns propagation delay meets the timing constraints of the target circuit. Consider the TSSOP package dimensions if space-constrained surface-mount assembly is necessary.

Part Context

This part belongs to the SN74HC138 family of decoders and demultiplexers manufactured by Texas Instruments. The family is characterized by high-speed CMOS technology, offering performance comparable to LS-TTL but with lower power consumption. The SN74HC138 is widely used in digital logic designs requiring address decoding or signal distribution across multiple lines.

Replacement Considerations

Compatible substitutes include SN74HC138DR (SOIC-16), SN74HC138DBR (SSOP-16), and SN74HC138PWR (TSSOP-16). Verify pinout compatibility and package dimensions before substitution.