DM74ALS251N

Overview

The DM74ALS251N is a 3-STATE 1-of-8 Line Data Selector/Multiplexer manufactured by onsemi (formerly Fairchild Semiconductor). It operates within a supply voltage range of 4.5 V to 5.5 V and supports an operating temperature range of 0 °C to +70 °C. The device features full on-chip decoding for selecting one of eight data sources using a three-bit binary code at the Select inputs. It provides two complementary outputs: Y (non-inverting) and W (inverting), both capable of high impedance OFF-State via an Output Control input. Propagation delays from Select inputs range from 5 ns to 24 ns, while data path delays range from 2 ns to 15 ns.

Feature Summary

• Provides full on-chip decoding to select one of eight data sources based on a unique three-bit binary code at the Select inputs.
• Features two complementary outputs offering both inverting and non-inverting buffer operation with high impedance capability.
• Incorporates internal overlap features in Select input buffers to prevent invalid output transients during selection changes.
• Output control circuitry includes a power-up 3-STATE feature to ensure safe initialization.

Applications

• Data routing in digital systems requiring selection among multiple input lines.
• Bus interface applications utilizing 3-STATE outputs to prevent bus access conflicts.
• Logic designs requiring simultaneous inverting and non-inverting signal paths.

Procurement Notes

Verify component authenticity through authorized distributors or direct manufacturer channels. Confirm package integrity and pin alignment against the N16E specification. Check manufacturing date codes as this component may be subject to obsolescence notices. Ensure compliance with RoHS directives if required for the specific application environment.

Selection Notes

Select this component when a 1-of-8 multiplexer with complementary outputs is required. It is functionally compatible with LS family counterparts but offers improved switching performance due to the Advanced Schottky TTL process. Consider the PDIP-16 package for through-hole mounting requirements. Verify that the propagation delay specifications meet the timing constraints of the target system design.

Part Context

This part belongs to the 74ALS logic series, utilizing advanced oxide-isolated, ion-implanted Schottky technology. It is designed to replace or upgrade older LS family components while maintaining pin compatibility. The DM74ALS251N specifically addresses applications needing fast data selection with dual output polarities.

Replacement Considerations

The datasheet notes functional compatibility with LS family counterparts. Specific substitute part numbers are not explicitly listed in the provided documentation; verify cross-reference availability with current manufacturers.