74LCX540WM

Overview

The Fairchild Semiconductor 74LCX540WM is a low voltage octal buffer and line driver featuring inverting logic with three-state outputs. It operates within a supply voltage range of 2.0 V to 3.6 V, supporting high-speed data transmission. The device incorporates 5V tolerant inputs and outputs, allowing safe interfacing between 1.8 V, 2.5 V, and 3.3 V logic systems and legacy 5 V environments. Packaged in a 20-lead SOIC (M20B) format, it provides eight independent channels for bus-oriented applications.

Feature Summary

• Provides eight independent inverting buffer channels with three-state output control for efficient bus management.
• Features 5V tolerant I/O architecture, enabling direct interface between low-voltage logic families and 5V systems without level shifting components.
• Designed for low power consumption and high-speed performance suitable for portable and battery-operated electronic devices.

Applications

• Memory address and data bus drivers
• Clock signal distribution and buffering
• Bus-oriented transmitter and receiver circuits

Procurement Notes

Verify the specific suffix M20B to confirm the 20-lead SOIC package configuration. Confirm current production status as datasheets indicate this component may be obsolete or discontinued by Fairchild Semiconductor. Ensure compatibility with existing PCB footprints and reflow soldering profiles before integration into new designs.

Selection Notes

Select this component when designing systems requiring octal buffering with mixed voltage domains. It is appropriate for applications needing 5V tolerance on both input and output sides while operating from a single low-voltage supply. Consider alternative LCX series variants if different package types or non-inverting logic functions are required.

Part Context

This part belongs to the 74LCX family of low-voltage CMOS logic devices. It shares functional similarities with other octal buffers like the 74HC540 but offers superior voltage tolerance characteristics. The device is distinct from the MM74HC540WM, which operates at higher voltages and lacks the specific 5V tolerance features documented for the LCX series.

Replacement Considerations

Public confirmed substitute part numbers include the 74LCX540MTC. Verify pinout compatibility and electrical specifications against the original datasheet before substitution.