SN74HC257D

Overview

The SN74HC257D is a quad 2-line to 1-line data selector/multiplexer with 3-state outputs manufactured by Texas Instruments. It operates within a supply voltage range of 2 V to 6 V and features non-inverted outputs. The device utilizes an SOIC-16 package with dimensions of 9.90 mm x 3.90 mm. Recommended operating conditions specify a temperature range of -40°C to +85°C. Electrical characteristics include a maximum propagation delay of 25 ns at 4.5 V, high-current inverting outputs capable of driving up to 15 LSTTL loads, and low power consumption with a maximum ICC of 80 µA.

Feature Summary

• Provides bus interface capabilities from multiple sources in high-performance systems
• Features 3-state outputs that do not load data lines when output-enable is high
• Includes clamp diodes on inputs to allow interfacing with voltages exceeding VCC

Applications

• Multiplexing signals from 4-bit data sources to 4-output data lines
• Bus-oriented system data routing
• High-performance system signal selection

Procurement Notes

Verify the specific ordering suffix against the manufacturer's current Package Option Addendum to confirm production status and lead finish. The 'SN74HC257D' designation without a trailing letter indicates an obsolete status in the provided documentation; ensure the active revision matches project requirements. Confirm RoHS compliance and moisture sensitivity level ratings prior to procurement.

Selection Notes

Select this component for applications requiring non-inverted quad multiplexing with 3-state outputs. Ensure the design accommodates the specified 2 V to 6 V supply voltage range and the -40°C to +85°C operating temperature. Verify that the SOIC-16 package footprint aligns with the PCB layout guidelines provided in the datasheet.

Part Context

This device belongs to the SNx4HC257 family of quadruple 2-line to 1-line data selectors/multiplexers. It shares functional similarities with the SN74HC258, which provides inverted outputs instead of non-inverted ones. Both devices are part of the HC logic series designed for CMOS technology.

Replacement Considerations

The SN74HC257DR is an active production version of the same device in the SOIC package. For inverted output functionality, the SN74HC258D serves as the logical counterpart.