MC74ACT245MELG

Overview

The MC74ACT245MELG is an octal bidirectional transceiver with 3-state inputs and outputs, belonging to the 74ACT logic series. It operates within a supply voltage range of 4.5 V to 5.5 V. The device features non-inverting buffers with a propagation delay of up to 9.0 ns at 5.0 V. It provides high current sinking and sourcing capabilities of 24 mA at both A and B ports. The component supports TTL-compatible inputs and includes dedicated Transmit/Receive and Output Enable control signals for bus-oriented applications.

Feature Summary

• Features eight non-inverting bidirectional buffers with 3-state outputs suitable for bus-oriented applications
• Provides strong output drive capability with 24 mA source and sink currents at both A and B ports
• Includes TTL-compatible inputs for direct interfacing with TTL logic systems
• Utilizes common Output Enable and Transmit/Receive inputs for direction and state control

Applications

• Bus-oriented data transmission systems
• TTL-to-CMOS level translation interfaces
• Bidirectional data buffering in microprocessor systems

Procurement Notes

Verify that the specific ordering suffix matches the required package type and lead-free status. Confirm the manufacturer's part number against official onsemi documentation to ensure compatibility with system requirements. Check for any recent product change notifications regarding marking or packaging updates.

Selection Notes

Select this component when TTL-compatible inputs are required alongside CMOS output levels. Ensure the operating voltage remains within the 4.5 V to 5.5 V range. Consider the 24 mA drive strength for driving multiple loads or longer traces compared to standard AC variants.

Part Context

This device is part of the MC74AC245/MC74ACT245 family manufactured by onsemi. It shares the same functional block diagram as the AC variant but differs in input threshold characteristics to support TTL compatibility. The family offers octal bidirectional buffering with 3-state outputs for various industrial and commercial logic applications.

Replacement Considerations

MC74AC245DWG

FAQ

What is the function of the T/R input?

The Transmit/Receive (T/R) input determines the direction of data flow. An active-HIGH signal enables data transfer from A ports to B ports, while an active-LOW signal enables transfer from B ports to A ports.

How does the OE input affect the outputs?

When the Output Enable (OE) input is HIGH, both A and B ports are disabled and placed in a High-Z state, regardless of the T/R input setting.