DM74ALS157N

Overview

The DM74ALS157N is a quad 2-line to 1-line data selector/multiplexer manufactured by Fairchild Semiconductor. It belongs to the Advanced Low-power Schottky (ALS) logic family and operates within a supply voltage range of 4.5 V to 5.5 V. The device features buffered inputs and outputs, providing full on-chip data selection to four output gates with a separate strobe input. A 4-bit word is selected from one of two sources and routed to the four outputs, presenting true data at the outputs. Typical propagation delay time is 9 ns, and typical power dissipation is 49 mW.

Feature Summary

• Contains inverters and drivers to supply full on-chip data selection to four output gates
• Features buffered inputs and outputs for improved signal integrity
• Includes a separate strobe input for controlling data routing

Applications

• Data selection in digital systems
• Routing 4-bit words from multiple sources to outputs
• Expanding data input points in circuit designs

Procurement Notes

Verify the manufacturer marking matches Fairchild Semiconductor or its successor entities such as onsemi, as corporate acquisitions may affect branding. Confirm the package type corresponds to the 16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide, specifically identified by the 'N' suffix. Ensure the component meets the ALS series specifications regarding voltage and switching characteristics.

Selection Notes

Select this component when a quad multiplexer with buffered I/O is required in an ALS logic environment. The DM74ALS157N offers faster switching speeds compared to standard LS series devices while maintaining lower power consumption than standard TTL. Consider the PDIP-16 package for through-hole mounting requirements and verify compatibility with 4.5 V to 5.5 V supply rails.

Part Context

The DM74ALS157N is part of the DM74ALS series of logic integrated circuits produced by Fairchild Semiconductor. This series utilizes Advanced Low-power Schottky technology to provide enhanced performance over previous generations. The specific model functions as a multiplexer, allowing the selection of data inputs for processing in digital logic applications.

Replacement Considerations

The DM74ALS158 is a related device within the same product family that provides inverted data outputs instead of true data. Verify if the application requires true or inverted logic levels before substituting.