CD74HCT640E

Overview

The CD74HCT640E is an octal bus transceiver from the Texas Instruments CD74HCT series, designed for high-speed CMOS logic applications. It features eight independent bidirectional data channels with inverting functionality and three-state outputs. The device operates within a supply voltage range of 4.5 V to 5.5 V and supports propagation delays typical of HCT technology. Packaged in a standard 20-pin DIP format, it is suitable for industrial temperature ranges extending from -55°C to +125°C.

Feature Summary

• Provides eight bidirectional data paths with inverting logic function
• Features three-state outputs for effective bus isolation
• Compatible with TTL input levels via HCT technology
• Supports wide industrial operating temperature ranges

Applications

• Bidirectional data bus transmission systems
• Memory interface circuits requiring isolation
• Industrial control logic interfaces
• High-speed digital signal routing

Procurement Notes

Verify the package type matches the required E suffix for PDIP-20 configuration. Confirm the HCT logic family compatibility with existing system voltage levels. Ensure the component meets specific industrial temperature requirements if deployed in harsh environments. Cross-reference datasheet revisions for any pinout or electrical characteristic updates before final integration.

Selection Notes

Select this component when eight-channel bidirectional transfer with inversion is required. The HCT series ensures compatibility with standard TTL logic inputs while maintaining CMOS noise immunity. Consider the PDIP-20 package for through-hole prototyping or legacy board designs. Evaluate propagation delay specifications against system timing constraints to ensure signal integrity at target clock speeds.

Part Context

This part belongs to the CD74HC/HCT640 family of octal bus transceivers. It shares functional similarities with other members like the CD74HC640M but differs in input threshold characteristics due to the HCT technology. The E suffix specifically denotes the plastic dual-in-line package variant, distinguishing it from surface-mount options within the same logical family.

Replacement Considerations

Direct substitutes include the CD74HC640E for HC-level input thresholds or the SN74HCT640N for equivalent performance in alternative packaging. Verify pin compatibility and electrical parameters before swapping components to maintain circuit functionality.