SN74HC257DR

Overview

The SN74HC257DR 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 supports an operating temperature from -40 °C to +85 °C. The device features a typical propagation delay of 9 ns at 5 V, low input current of 1 µA maximum, and high-current inverting outputs capable of driving up to 15 LSTTL loads. It is housed in a 16-pin SOIC package.

Feature Summary

• Provides bus interface capabilities for multiple sources in high-performance systems
• Features active-low strobe inputs that force all outputs into a high-impedance state
• Designed to multiplex signals from 4-bit data sources to 4-output data lines

Applications

• Data selection
• Multiplexing
• Bus interface systems

Procurement Notes

Verify the specific ordering suffix 'DR' corresponds to the SOIC-16 package and tape-and-reel carrier configuration. Confirm RoHS compliance status and lead finish details against the latest manufacturer documentation before finalizing procurement specifications.

Selection Notes

Select this component when a wide operating voltage range between 2 V and 6 V is required. Ensure the design accommodates the specified propagation delays and output drive currents. Verify that the 16-pin SOIC footprint aligns with the target PCB layout constraints.

Part Context

This part belongs to the SNx4HC257 family of quadruple 2-line to 1-line data selectors. It shares functional similarities with the SN74HC258 but provides non-inverted outputs instead of inverted ones. Both devices utilize shared address select and active-low strobe inputs for channel control.

Replacement Considerations

SN74HC257D (Tube packaging)

FAQ

How does the active-low strobe input affect the outputs?

A high level at the G terminal forces all outputs into the high-impedance state.

What is the function of the A/B input?

The A/B input serves as the address select line to choose between the two data sources for each channel.