SN74LS42NSRE4

Overview

The SN74LS42NSRE4 is a Low Power Schottky (LS) TTL BCD-to-decimal decoder manufactured by Texas Instruments. It converts four binary-coded decimal inputs into one of ten active-low outputs. The device operates within a supply voltage range of 4.75 V to 5.25 V and features a propagation delay of 30 ns. It is housed in a 16-pin SOIC package with a wide lead pitch, suitable for surface-mount assembly. The component supports commercial temperature ranges from 0°C to +70°C.

Feature Summary

• Executes translation of 4-bit binary coded decimal input signals into distinct active-low decimal output lines.
• Utilizes Low Power Schottky technology to balance switching speed with reduced power consumption.
• Provides robust noise immunity and defined logic levels compatible with standard TTL circuits.

Applications

• Decoding binary addresses in memory addressing systems
• Driving decimal display indicators or control panels
• Implementing sequential control logic in industrial automation

Procurement Notes

Verify the specific suffix 'RE4' indicates lead-free composition and RoHS compliance during sourcing. Confirm the SOIC-16 package dimensions match the target PCB footprint. Ensure the supplier provides valid traceability documentation for the Texas Instruments manufacturing origin. Cross-reference the date code to confirm availability within the required operational timeline.

Selection Notes

Select this component when a single-channel BCD-to-decimal decoding function is required in a surface-mount design. The LS series offers an optimal trade-off between speed and power dissipation for general-purpose logic applications. Verify that the system voltage remains strictly within the 4.75 V to 5.25 V operating window to ensure reliable signal integrity and prevent undefined logic states.

Part Context

This part belongs to the SN74LS family of integrated circuits, which are widely used in digital logic designs requiring moderate speeds. The SN74LS42 specifically addresses the need for direct BCD-to-decimal conversion without external gating. It serves as a foundational building block for older digital systems and legacy interface designs where TTL compatibility is mandatory.

Replacement Considerations

The SN74LS42N is a verified through-hole equivalent offering identical logical functionality. For surface-mount requirements, verify pinout compatibility with other SN74LS42 variants before substitution. Ensure any replacement maintains the same LS logic family characteristics to preserve timing margins.