TC74AC540FT(EL)

Overview

The TC74AC540FT(EL) is an octal bus buffer manufactured by Toshiba Semiconductor and Storage, utilizing advanced high-speed CMOS technology. It features eight inverting outputs with three-state capability controlled by inputs 1G and 2G. The device operates within a supply voltage range of 2.0 V to 5.5 V and supports an operating temperature from -40°C to +85°C. Key electrical parameters include a typical propagation delay of 4.0 ns at 5 V, maximum quiescent current of 8 μA, and symmetrical output drive currents of 24 mA minimum for both high and low states.

Feature Summary

• Inverts input signals while providing three-state output control via dedicated enable pins.
• Maintains low power dissipation comparable to standard CMOS logic families.
• Provides high noise immunity through defined voltage thresholds relative to the supply voltage.
• Features balanced propagation delays between low-to-high and high-to-low transitions.

Applications

• High-speed data bus buffering applications
• Driving 50 Ω transmission lines
• Memory address register buffering

Procurement Notes

Verify that the specific ordering suffix matches the required package type, as the FT designation indicates TSSOP-20 packaging. Confirm RoHS compliance status directly with the manufacturer or authorized distributors prior to procurement. Ensure design reviews account for the absolute maximum ratings to prevent device degradation during operation.

Selection Notes

Select this component when inverting functionality is required for octal bus architectures. Compare against the non-inverting TC74AC541 variant if signal polarity preservation is necessary. Evaluate the 2.0 V to 5.5 V operating range to ensure compatibility with the target system's power supply rails and logic levels.

Part Context

This part belongs to the TC74AC540/541 series of octal bus buffers. It is functionally compatible with the 74F540/541 logic families but utilizes CMOS technology for lower power consumption. The series includes DIP, SOP, and TSSOP package options, with the FT variant specifically denoting the thin-shrink small-outline package configuration.

Replacement Considerations

The TC74AC541FT(EL) serves as the direct non-inverting counterpart within the same series. Cross-referencing with other manufacturers' 74AC540 equivalents requires verification of pinout compatibility and electrical parameter alignment.

FAQ

How are the outputs controlled?

The outputs enter a high-impedance state when either input 1G or 2G is held high. Normal operation occurs only when both enable inputs are low.

What is the purpose of the symmetrical output impedance?

The symmetrical output impedance allows the device to effectively drive 50 Ω transmission lines without requiring external termination components for signal integrity.