SN74HC257NSR

Overview

The SN74HC257NSR is a high-speed CMOS logic device featuring four independent 2-line to 1-line data selectors or multiplexers with non-inverting three-state outputs. It operates within a supply voltage range of 2 V to 6 V and supports an operating temperature range from -40 °C to +85 °C. The component utilizes a 16-pin Small Outline Package (SOP) designated as NS. Electrical specifications include a maximum propagation delay of 25 ns at 4.5 V, low input current of 1 µA maximum, and output drive capabilities of ±6 mA at 5 V.

Feature Summary

• Provides bus interface functionality by allowing multiple sources to connect to high-performance systems without loading data lines when disabled.
• Features active-low strobe inputs that force all outputs into a high-impedance state, preventing interference during power-up or power-down sequences.
• Designed for high-current driving capability, enabling the device to load up to 15 LSTTL loads while maintaining low power consumption.

Applications

• Data selection in digital systems
• Multiplexing signals from 4-bit data sources to 4-output data lines
• Bus interface applications requiring multiple source connectivity

Procurement Notes

Verify the specific package designation 'NS' corresponds to the 16-pin SOP outline provided in the datasheet. Confirm RoHS compliance status and lead finish details via the manufacturer's orderable addendum. Ensure the ordering suffix matches the required tape and reel quantity specifications for automated assembly processes.

Selection Notes

Select this component for designs requiring quad 2-to-1 multiplexing with three-state outputs. The HC series offers a wide voltage range suitable for various logic families. Consider the SOP package dimensions for PCB layout constraints. Verify that the propagation delay meets the system timing requirements under the intended operating voltage and load conditions.

Part Context

This part belongs to the SNx4HC257 family of quadruple 2-line to 1-line data selectors/multiplexers. It is functionally similar to the SN74HC258, which provides inverted outputs instead of non-inverting ones. The device is part of Texas Instruments' standard catalog line, distinct from military-grade SN54 variants which offer extended temperature ranges.

Replacement Considerations

SN74HC258NSR: Offers identical pinout and functionality but provides inverted outputs rather than non-inverting outputs. SN74HC257DR: Identical electrical performance housed in a SOIC package instead of SOP.