MC74ACT540N

Overview

The MC74ACT540N is an octal buffer and line driver manufactured by onsemi, belonging to the 74ACT logic series. It features eight non-inverting outputs with three-state capability, allowing for high-impedance isolation when disabled. The device operates within a supply voltage range of 4.5 V to 5.5 V and supports input levels compatible with TTL standards. Designed for surface-mount applications, it utilizes a 20-pin Small Outline package. Key electrical characteristics include a propagation delay of 7.5 ns at 5 V, output drive currents of ±24 mA, and a static current of 8 µA. It functions reliably across an industrial temperature range from -40°C to +85°C.

Feature Summary

• Three-state outputs enable bus isolation and prevent signal interference when the device is disabled.
• TTL-compatible inputs allow direct interfacing with standard TTL logic circuits without additional level shifting.
• Octal architecture provides eight independent buffering channels in a single integrated circuit.
• High output drive capability supports connection to multiple loads or long transmission lines.

Applications

• Memory address and data bus driving
• Clock signal distribution and buffering
• Microprocessor I/O port expansion
• Bidirectional bus transceivers

Procurement Notes

Verify the specific suffix 'N' against official datasheets to confirm package type and tape/reel specifications. Ensure compatibility with RoHS directives if environmental compliance is required. Cross-reference pinout configurations with target PCB layouts to avoid orientation errors during assembly. Confirm operating temperature ranges match system requirements.

Selection Notes

Select this component when eight buffered outputs with tri-state control are needed for bus architectures. Consider the ACT series for faster switching speeds compared to standard AC variants. Verify that the 5V supply voltage aligns with the system power rails. Evaluate thermal dissipation requirements given the 200 mW power dissipation rating under load conditions.

Part Context

This part belongs to the MC74AC(T)540/541 family of octal buffers and line drivers. It serves as a non-inverting counterpart to the MC74ACT540, which offers inverting functionality. The family shares similar electrical characteristics but differs in logical polarity. These devices are commonly used in digital systems requiring signal isolation and amplification for reliable data transmission across buses.

Replacement Considerations

MC74ACT541DTG: Octal buffer with non-inverting outputs in TSSOP-20 package. MC74ACT540DWR2G: Octal buffer with inverting outputs in SOIC-20 package. MC74AC540: Non-TTL compatible version of the same functional block.