CD74HCT640M

Overview

The CD74HCT640M is an octal bus transceiver from the Texas Instruments 74HCT logic family, housed in a 20-pin SOIC package. It operates on a single supply voltage ranging from 4.5 V to 5.5 V and features three-state outputs. The device provides TTL-compatible CMOS inputs and supports bidirectional data transfer with eight channels. It includes an active-low output enable input and an active-low direction control input to manage signal flow between ports A and B.

Feature Summary

• Provides bidirectional data transmission across eight independent channels
• Features TTL-compatible CMOS inputs for robust noise immunity
• Includes active-low output enable and direction control inputs

Applications

• Memory mapping controllers
• Clock drivers
• Bus-oriented architectures

Procurement Notes

Verify the specific suffix 'M' corresponds to the SOIC-20 surface-mount package configuration. Confirm RoHS compliance status through the manufacturer's official documentation. Ensure the operating temperature range meets system requirements, as industrial variants may differ. Cross-reference the datasheet revision date to validate electrical characteristics against current design standards.

Selection Notes

Select this component when interfacing systems requiring TTL-level compatibility with CMOS logic families. The HCT series ensures reliable operation at standard 5V logic levels. Consider the propagation delay specifications for high-speed bus applications. Verify that the package dimensions fit the available PCB footprint constraints.

Part Context

This part belongs to the 74HC(H)T640 family of octal bus transceivers. It shares functional similarities with other members like the CD74HC640 but differs in input threshold voltages due to the HCT technology. The family is designed for general-purpose digital logic applications requiring wide voltage tolerance and high drive capability.

Replacement Considerations

Check for direct pin-compatible alternatives within the same logic family. Verify if lower-cost or newer-generation revisions are available from the manufacturer. Ensure substitute parts maintain identical package dimensions and electrical parameters.