MC74AC240N

Overview

The MC74AC240N is an octal bus buffer with inverted outputs and three-state capabilities, manufactured by onsemi. It operates within a supply voltage range of 2V to 6V and features a 20-PDIP package. The device provides symmetrical output impedance with high-level and low-level output currents of 24mA each. It includes two functional elements, each handling four bits, for a total of eight inputs and outputs. The component supports through-hole mounting and functions across a temperature range of -40°C to 85°C.

Feature Summary

• Octal bus buffering with inverted logic functionality
• Three-state output capability for bus isolation
• Symmetrical output drive strength for transmission line applications

Applications

• Memory address and data bus driving
• Clock signal distribution
• Microprocessor system interface circuits

Procurement Notes

Verify the obsolete status of this specific part number before procurement planning. Confirm that equivalent replacement components from other manufacturers meet all electrical specifications and pinout compatibility requirements for your design. Ensure that any substitute devices support the required operating voltage range and package type to maintain circuit integrity without redesign.

Selection Notes

Select this component when designing systems requiring octal buffering with inverted outputs in a through-hole package. Consider the 2V to 6V operating range and 24mA drive capability for load requirements. Evaluate alternative packages or manufacturers if the discontinued status impacts long-term supply chain stability or if surface-mount solutions are preferred for modern PCB layouts.

Part Context

This component belongs to the 74AC logic family, characterized by CMOS technology and high-speed operation. It is functionally similar to other octal buffers like the MC74AC540 but differs in pin configuration and inversion polarity. The AC series offers improved speed over standard 74LS logic while maintaining low power consumption, making it suitable for general-purpose digital buffering tasks in industrial and consumer electronics.

Replacement Considerations

Public confirmed substitutes include CD74AC240E and SN74AC240N from Texas Instruments.