74AC138PC

Overview

The Fairchild Semiconductor 74AC138PC is a 1-of-8 decoder and demultiplexer belonging to the AC logic series. It operates within a supply voltage range of 2 V to 6 V and features a 16-pin PDIP package with through-hole mounting. The device supports an industrial operating temperature range from -40 °C to +85 °C. It includes three enable inputs to facilitate cascading or data reception functions.

Feature Summary

• Provides one-of-eight decoding based on binary select inputs
• Incorporates three enable inputs for system expansion control
• Features fully buffered inputs to minimize driving circuit load

Applications

• High-performance memory decoding systems
• Data routing applications requiring short propagation delays
• Demultiplexing circuits utilizing enable inputs as data lines

Procurement Notes

Verify component authenticity and physical condition upon receipt, as this part may be subject to obsolescence or limited availability. Confirm that the packaging integrity remains intact to prevent damage to the DIP leads. Ensure compliance with relevant environmental standards required for your specific assembly process before integration into production.

Selection Notes

Select this component when a CMOS-based 3-to-8 decoder with wide voltage tolerance is required. The AC series offers higher speed than standard HC devices while maintaining low power consumption. Verify that the 16-pin DIP form factor aligns with existing PCB footprints and that the industrial temperature rating meets operational environmental constraints.

Part Context

This decoder is part of the broader 74AC logic family, designed for high-speed digital applications. It serves as a functional equivalent to other industry-standard 3-to-8 decoders but utilizes advanced CMOS technology. The device is commonly used in conjunction with microprocessors and memory arrays for address decoding and signal distribution tasks.

Replacement Considerations

Direct substitutes include MC74AC138N (onsemi) and DM74AC138 (Fairchild). Alternative compatible parts are 74ACT138SC (onsemi) for surface mount needs and 74F138SDC (Fairchild) for TTL-compatible environments. Verify pinout compatibility and electrical specifications before substitution.