DM74LS240SJ

Overview

The DM74LS240SJ is an octal 3-state buffer and line driver manufactured by Fairchild Semiconductor. It features two independent 4-bit elements with inverting outputs, housed in a 20-pin Small Outline Integrated Circuit (SOIC) package. The device operates within a supply voltage range of 4.75 V to 5.25 V. It supports high-current output capabilities, providing 15 mA at logic high and 64 mA at logic low levels. The component is designed for through-hole or surface-mount applications depending on the specific variant, though the SJ suffix typically denotes SOIC. It functions as a line receiver and driver for digital systems.

Feature Summary

• Provides dual 4-bit buffering with inverting functionality
• Features 3-state outputs for bus-oriented designs
• Supports high-current driving capabilities for line transmission

Applications

• Bus-oriented memory and data register systems
• Clock drivers and timing circuits
• Line receivers and transmitters in communication interfaces

Procurement Notes

Verify the exact package type and pinout configuration against the official Fairchild Semiconductor datasheet before integration. Confirm that the DM74LS240SJ designation corresponds to the 20-SOP variant rather than DIP packages used by other manufacturers. Ensure compatibility with existing PCB footprints and soldering profiles for SOIC components. Check for any specific ordering suffixes that may indicate temperature grades or packaging variations.

Selection Notes

Select this component when designing systems requiring octal buffering with 3-state control. It is suitable for applications needing high current drive capability compared to standard LS series devices. Consider the inverting nature of the outputs when mapping signal paths. Verify that the operating temperature range meets the environmental requirements of the target application.

Part Context

This part belongs to the 74LS family of logic integrated circuits, known for low-power Schottky technology. The DM74LS240 series specifically provides octal buffers with 3-state outputs. Fairchild Semiconductor, now part of ON Semiconductor, produced this component for general-purpose digital logic applications. The SJ suffix indicates the small outline package format.

Replacement Considerations

Cross-reference with DM74LS240N from Texas Instruments or ON Semiconductor for equivalent functionality. Verify pin compatibility and electrical specifications before substitution. Ensure the replacement part matches the 20-pin SOIC package dimensions if space constraints are critical.