74FCT240ASCX

Buffers, Drivers, Receivers, Transceivers Overview

The National Semiconductor 74FCT240ASCX is an octal buffer and line driver utilizing FCT logic technology. It features inverting outputs with three-state control via active-low enable inputs (1OE, 2OE). The device employs a BiCMOS process to limit output-high voltage swing to approximately 3.7V at VCC=5V, reducing power bus ringing and EMI. It provides high sink currents ranging from 48mA to 64mA and controlled output edge rates. Typical propagation delay is 4.1ns at 5V and 25°C.

Buffers, Drivers, Receivers, Transceivers Feature Summary

• Inverting octal buffer configuration with three-state outputs
• BiCMOS technology limits output-high voltage to reduce EMI and ground bounce
• High drive capability with 48mA to 64mA output sink current
• Controlled output edge rates for signal integrity

Buffers, Drivers, Receivers, Transceivers Applications

• High-speed data bus buffering
• Clock distribution networks
• Memory interface drivers
• System backplane interconnects

Buffers, Drivers, Receivers, Transceivers Procurement Notes

Verify the manufacturer origin carefully, as Harris Semiconductor was acquired by Texas Instruments. Confirm that the specific 'ASCX' suffix corresponds to the intended package and temperature grade within the CD54/74FCT240 family documentation. Ensure compatibility with existing design specifications regarding the limited output voltage swing.

Buffers, Drivers, Receivers, Transceivers Selection Notes

Select this component when inverting functionality and three-state isolation are required for octal buses. Consider the reduced output voltage swing (approx. 3.7V) for compatibility with downstream CMOS loads. Evaluate the BiCMOS process benefits for applications sensitive to simultaneous switching noise and ground bounce compared to standard CMOS alternatives.

Buffers, Drivers, Receivers, Transceivers Part Context

This part belongs to the FCT (Fast CMOS) logic family, bridging the speed of bipolar logic with CMOS power efficiency. The 74FCT240 specifically addresses the need for high-drive, low-noise buffering in systems requiring fast transition times and significant current sinking capabilities while maintaining low quiescent power consumption.

Buffers, Drivers, Receivers, Transceivers Replacement Considerations

Compatible substitutes include other FCT series octal buffers such as the 74FCT244 (non-inverting) or equivalent parts from Texas Instruments and Renesas. Verify pinout compatibility and ensure the replacement supports the required 48mA-64mA sink current and three-state operation.