DM74S138N

Overview

The DM74S138N is a Schottky-clamped 3-to-8 line decoder/demultiplexer manufactured by onsemi. It operates within a supply voltage range of 4.75 V to 5.25 V and features three enable inputs (one active-HIGH, two active-LOW) for simplified cascading. The device utilizes a 16-lead Plastic Dual-In-Line Package (PDIP). Propagation delays from select inputs to outputs range from 2 ns to 14 ns depending on load conditions. Typical power dissipation is 245 mW.

Feature Summary

• Schottky clamping for high performance and reduced line-ringing
• Three enable inputs simplify system expansion without external inverters
• Fully buffered inputs presenting only one normalized load

Applications

• High-performance memory decoding systems
• Data routing applications requiring short propagation delay
• Data transmission systems

Procurement Notes

Verify the manufacturer origin as Fairchild Semiconductor or its successor entities like onsemi. Confirm the package type matches the 16-lead PDIP specification. Ensure the logic family corresponds to the 74S series characteristics. Check for RoHS compliance status if required for specific manufacturing environments.

Selection Notes

Select this component when low propagation delay is critical for memory access timing. The three enable inputs allow for complex decoding configurations without additional logic gates. Verify that the operating temperature range of 0°C to +70°C meets the environmental requirements of the target application.

Part Context

This part belongs to the 74S logic family, known for high-speed operation using Schottky technology. It is functionally related to the DM74S139, which contains two independent 2-to-4 line decoders in the same package. Both devices share similar electrical characteristics and packaging options.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.