74LVC245ATTR

Overview

The STMicroelectronics 74LVC245ATTR is a low-voltage CMOS octal bus transceiver featuring non-inverting three-state outputs. It operates within a supply voltage range of 1.65V to 3.6V, with data retention supported down to 1.2V. The device provides high-speed performance with a maximum propagation delay of 6.3ns at VCC = 3V and symmetrical output impedance where |IOH| equals IOL at a minimum of 24mA at 3V. Inputs are tolerant up to 5.5V, enabling direct interfacing with 5V logic systems.

Feature Summary

• Features power-down protection on all inputs and outputs to minimize leakage current during standby modes.
• Provides five hundred milliamp latch-up performance exceeding JESD 17 standards for enhanced reliability.
• Includes electrostatic discharge protection circuits offering immunity greater than 2000V under human body model testing.

Applications

• Two-way asynchronous communication between data buses
• Low-power and low-noise applications in portable electronics
• Interfacing 1.65V to 3.6V logic systems with 5V environments

Procurement Notes

Verify the component matches the specific TSSOP-20 package configuration indicated by the ATTR suffix. Confirm that the operating environment remains within the specified -55°C to +125°C temperature range. Ensure input signals do not exceed the absolute maximum ratings defined in the datasheet to prevent permanent damage to the silicon gate structure.

Selection Notes

Select this component when bidirectional data transfer is required between buses operating at different voltage levels. The wide input voltage tolerance allows seamless integration with legacy 5V systems while maintaining low power consumption. Consider the propagation delay specifications if the application demands strict timing constraints for high-frequency signal transmission.

Part Context

This device belongs to the 74LVC series of low-voltage CMOS logic integrated circuits manufactured using sub-micron silicon gate technology. It serves as an octal bus transceiver designed for efficient data routing in mixed-voltage digital systems. The architecture supports easy cascading through dedicated enable and direction control inputs.

Replacement Considerations

Check for pin-compatible alternatives such as the SN74LVC245 from Texas Instruments or the 74LVC245 from NXP Semiconductors. Verify that substitute parts maintain identical electrical characteristics, specifically the 5V tolerant input capability and the 24mA output drive strength at the target supply voltage.

FAQ

How does the device handle floating bus terminals?

All floating bus terminals must be held HIGH or LOW during the High Z state to ensure stable operation and prevent undefined logic levels.

What is the function of the DIR input?

The DIR input determines the direction of data transmission across the A and B buses, allowing for controlled two-way asynchronous communication.