DM74ALS138MX

Overview

The DM74ALS138MX is a 3-to-8 line decoder and demultiplexer manufactured by onsemi, utilizing an Advanced Low-power Schottky (ALS) process. It operates within a supply voltage range of 4.5V to 5.5V and supports a free-air operating temperature from 0°C to +70°C. The device features three binary select inputs and three enable inputs (one active-HIGH, two active-LOW) to decode one-of-eight outputs or route data. It is housed in a 16-lead Small Outline Integrated Circuit (SOIC) package.

Feature Summary

• Incorporates fully buffered inputs presenting only one normalized load to the driving circuit.
• Features high-performance Schottky diodes on all inputs to suppress line-ringing.
• Includes three enable inputs to simplify cascading and data reception without external gates.

Applications

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

Procurement Notes

Verify that the specific ordering code includes the 'X' suffix to confirm the SOIC tape and reel packaging configuration. Confirm the manufacturer origin, as this component was originally produced by Fairchild Semiconductor before acquisition by onsemi. Ensure the datasheet revision date aligns with your design requirements for electrical characteristics.

Selection Notes

Select this component when low power dissipation and high-speed performance are required for memory decoding. The ALS logic family offers a balance between speed and power consumption. Verify that the system voltage remains within the 4.5V to 5.5V range and that the thermal environment stays within the specified 0°C to +70°C operating limits.

Part Context

This part belongs to the 74ALS logic family, known for advanced oxide-isolated, ion-implanted Schottky TTL processes. The DM74ALS138 series specifically addresses the need for minimal system delay in high-speed environments where decoder latency must be negligible compared to memory access times.

Replacement Considerations

Check for equivalents such as the DM74ALS138M (tube packaging) if reel packaging is not strictly required. Other manufacturers may offer pin-compatible 74ALS138 variants, but verify electrical specifications against the original datasheet.

FAQ

How many enable inputs does the DM74ALS138MX have?

It has three enable inputs: one active-HIGH (G1) and two active-LOW (G2A and G2B).

What is the typical power dissipation of this device?

The typical power dissipation is 23 mW.