ET74LCX244

Overview

The ET74LCX244 is an octal non-inverting buffer and line driver manufactured by ETEK Microelectronics. It features eight 3-state outputs designed for low-voltage applications, specifically operating at 2.5V or 3.3V VCC. The device provides 5V tolerant inputs and outputs, enabling seamless interfacing with 5V signal environments. Fabricated using advanced CMOS technology, it ensures high-speed operation while maintaining low power dissipation. Key electrical characteristics include a maximum propagation delay of 6.5 ns at 3.3V and a maximum supply current of 10 µA. The outputs support ±24 mA drive current at 3.0V VCC.

Feature Summary

• Contains eight non-inverting buffers with 3-state outputs for bus-oriented transmission
• Provides 5V tolerance on both inputs and outputs for mixed voltage compatibility
• Supports live insertion and withdrawal capabilities to protect connected circuits
• Implements patented noise and EMI reduction circuitry for signal integrity

Applications

• Memory address drivers in low-voltage systems
• Clock distribution networks requiring high-speed buffering
• Bus-oriented transmitter and receiver interfaces
• Translators between 3.3V and 5V logic domains

Procurement Notes

Verify the specific package variant, such as the 20-QFN (2.5x3.5) configuration, against your PCB footprint requirements. Confirm that the manufacturer designation matches ETEK Microelectronics, as this part number may also be produced by other vendors under similar naming conventions. Ensure the datasheet version aligns with your design's electrical specifications, particularly regarding the 5V tolerance and output drive currents. Cross-reference the pinout diagram to guarantee correct orientation during assembly.

Selection Notes

Select this component when designing systems that require driving buses or memory interfaces with 3.3V logic while maintaining compatibility with 5V peripherals. The 5V tolerant I/O structure eliminates the need for additional level-shifting components in mixed-voltage designs. Consider the low power consumption and high-speed performance for battery-operated or thermally constrained applications. Verify that the required output drive current does not exceed the specified limits for your load conditions.

Part Context

This device belongs to the 74LCX series of low-voltage CMOS logic devices. It serves as a standard octal buffer solution for modern digital systems transitioning from 5V to lower voltage standards. The LCX family is characterized by its ability to interface directly with TTL levels while operating at reduced supply voltages. This specific model provides the necessary isolation and drive strength for complex bus architectures.

Replacement Considerations

Compatible substitutes include the STMicroelectronics 74LCX244, ON Semiconductor 74LCX244, and Fairchild Semiconductor 74LCX244. These parts share identical logical functions and electrical specifications. Verify pin compatibility and package dimensions before substitution to ensure mechanical fit within the existing design.

FAQ

What is the maximum propagation delay of the ET74LCX244?

The maximum propagation delay is 6.5 ns when operating at a VCC of 3.3V.

Can the ET74LCX244 interface directly with 5V signals?

Yes, the device features 5V tolerant inputs and outputs, allowing direct interfacing with 5V signal environments despite operating at lower supply voltages.

Does the ET74LCX244 support live insertion?

Yes, the device supports live insertion and withdrawal, which helps prevent damage to the system during hot-plugging operations.