DM74AS258N

Overview

The DM74AS258N is a 3-STATE Quad 1 of 2 Line Data Selector/Multiplexer in a 16-Lead Plastic Dual-In-Line Package (PDIP). It routes a 4-bit word from one of two sources to four outputs, presenting inverted data. Operating conditions include a supply voltage of 4.5V to 5.5V and an operating temperature range of 0°C to +70°C. Key electrical parameters at VCC = 5V include HIGH Level Input Voltage of 2V, LOW Level Input Voltage of 0.8V, HIGH Level Output Current of -15mA, and LOW Level Output Current of 48mA. Propagation delays for data inputs range from 14ns to 16ns, while select input delays range from 10ns to 29.5ns.

Feature Summary

• Provides 3-STATE buffer-type output drive capable of interfacing directly with bus lines
• Functionally and pin-for-pin compatible with Schottky, low power Schottky, and advanced low power Schottky TTL counterparts
• Utilizes advanced oxide-isolated, ion-implanted Schottky TTL process for improved AC performance
• Designed to minimize propagation delay time by presenting inverted data to the outputs

Applications

• Multiplexing dual data buses
• Expanding any data input point
• Implementing n-bit paralleled data selectors for data buses
• Source programmable counters

Procurement Notes

Verify component authenticity and datasheet alignment before procurement. The DM74AS258N is manufactured under Fairchild Semiconductor specifications, now part of onsemi. Confirm package type N16E matches design requirements. Check RoHS compliance status as original documentation may predate modern environmental directives. Ensure operating conditions align with system voltage and temperature constraints.

Selection Notes

Select the DM74AS258N when inverted data output is required for minimized propagation delay in bus-oriented systems. Choose this device over the DM74AS257 if signal inversion is necessary without additional logic gates. Consider the 3-STATE output capability for direct bus interfacing. Verify compatibility with existing Schottky TTL logic families for seamless integration into legacy or mixed-technology designs.

Part Context

The DM74AS258N belongs to the 74AS series of high-speed Schottky TTL logic devices. Originally produced by Fairchild Semiconductor, these components are designed for applications requiring fast switching speeds and robust drive capabilities. The 74AS family offers improved AC performance compared to standard Schottky and Low Power Schottky variants, making it suitable for high-frequency digital systems.

Replacement Considerations

Public confirmed substitute part numbers: SN74AS258N.