DM74AS157SJ

Overview

The DM74AS157SJ is a Quad 1 of 2 Line Data Selector/Multiplexer manufactured by onsemi, utilizing the Advanced Schottky (AS) logic series. It operates within a supply voltage range of 4.5V to 5.5V and supports an operating temperature range of 0°C to +70°C. The device features four independent multiplexing circuits in a 16-SOP package. Key electrical parameters include a maximum propagation delay of 11ns from Select to Output and 10.5ns from STROBE to Output. Output drive capabilities are specified at -2mA for high level and 20mA for low level.

Feature Summary

• Provides full on-chip data selection with inverters and drivers for four output gates.
• Includes a separate STROBE input to control data routing.
• Utilizes advanced oxide-isolated, ion-implanted Schottky TTL process for improved AC performance.
• Functionally and pin-for-pin compatible with Schottky, Low Power Schottky, and Advanced Low Power Schottky TTL counterparts.

Applications

• Multiplexing dual data buses
• Expanding any data input point
• Implementing general four functions of two variables where one variable is common

Procurement Notes

Verify component authenticity through authorized channels as this part may be discontinued or subject to obsolescence notices. Confirm that the specific SOP package variant matches design requirements. Review datasheet revisions for any changes in electrical characteristics or recommended operating conditions prior to finalizing procurement specifications.

Selection Notes

Select this component when high-speed data selection is required within standard TTL voltage ranges. The AS series offers superior switching speed compared to LS or ALS equivalents. Ensure the design accommodates the specific propagation delays associated with the Select and STROBE inputs. Verify thermal management capabilities given the power dissipation characteristics of the Schottky process.

Part Context

This device belongs to the Fairchild Semiconductor (now onsemi) DM74AS family of logic integrated circuits. It is part of a broader line of Advanced Schottky TTL devices designed for high-speed digital applications. The DM74AS157 is functionally paired with the DM74AS158, which provides inverted outputs, allowing designers to choose between true or inverted data presentation based on circuit timing requirements.

Replacement Considerations

Direct functional substitutes include the DM74LS157 and DM74ALS157, though these offer lower switching speeds. Other Advanced Schottky variants like the DM74AS158 provide inverted outputs. Cross-reference with Texas Instruments SN74AS157 for equivalent performance in the AS logic family.