MC74VHC245DT

Overview

The MC74VHC245DT is an octal bus transceiver fabricated with advanced high-speed CMOS technology. It provides bidirectional data transmission across two 8-bit ports with three-state outputs. The device operates within a voltage range of 2.0 V to 5.5 V, featuring balanced propagation delays and low power dissipation. It includes power-down protection on inputs and outputs, ensuring safe operation during system standby or hot-plugging scenarios.

Feature Summary

• Bidirectional data transfer between two 8-bit buses controlled by a direction pin
• Three-state outputs allowing electrical isolation when disabled
• Power-down protection prevents current leakage on I/O pins during low-voltage states
• Compatible with standard logic families for seamless system integration

Applications

• Memory mapping in computing systems
• Clock drivers and buffer circuits
• Bidirectional bus architectures requiring signal isolation

Procurement Notes

Verify the specific suffix 'DT' corresponds to the TSSOP-20 package configuration required for your PCB layout. Confirm that the operating voltage range of 2.0 V to 5.5 V aligns with your system's power supply rails. Ensure ESD handling procedures are followed during assembly due to the CMOS fabrication process.

Selection Notes

Select this component when bidirectional communication between 3.3 V and 5.0 V domains is required without level shifting circuitry. The VHC series offers faster switching speeds compared to HC variants while maintaining low power consumption. Verify that the load capacitance requirements of the connected buses fall within the specified limits for optimal signal integrity.

Part Context

This part belongs to the MC74VHC/VHCT family of octal bus transceivers designed for high-speed digital applications. The VHC variant specifically supports a wider voltage range down to 2.0 V compared to VHCT devices. It serves as a critical interface component in systems requiring reliable data routing between microprocessors and peripheral devices.

Replacement Considerations

MC74VHC245DTR2 (Reel version)

FAQ

Does the MC74VHC245DT support hot-swapping?

Yes, the device includes power-down protection on both inputs and outputs, allowing it to withstand voltage spikes when VCC is zero, which facilitates safe hot-swapping operations.

What is the function of the OE pin?

The Output Enable (OE) pin controls the state of the A and B ports. When OE is high, both ports are placed in a high-impedance state, effectively disconnecting them from the bus.