CD74HCT243EG4

Overview

The CD74HCT243EG4 is a high-speed CMOS logic quad-bus transceiver manufactured by Texas Instruments. It features three-state outputs and operates within a supply voltage range of 4.5 V to 5.5 V. The device utilizes HCT logic levels, ensuring TTL-compatible inputs while providing CMOS outputs. It is designed for surface-mount applications in a 14-pin SOIC package. Key electrical parameters include a maximum propagation delay of 20 ns at 4.5 V with a 50 pF load, and output drive currents of ±6 mA.

Feature Summary

• Quad-bus transceiver architecture supporting bidirectional data transfer across four channels
• Three-state outputs enabling direct connection to bus systems without additional buffering
• TTL-compatible input thresholds allowing seamless integration with legacy logic families
• High-speed CMOS technology optimized for low power consumption and fast switching

Applications

• Bidirectional data bus drivers for microprocessor-based systems
• Memory address and data bus driving in computer architectures
• I/O port expansion circuits requiring level shifting between TTL and CMOS domains
• Bus-oriented memory and control signaling interfaces

Procurement Notes

Verify the specific suffix 'EG4' against official Texas Instruments documentation to confirm lead-free status and RoHS compliance details. Ensure the ordering part number matches the exact package variant required for your PCB footprint. Cross-reference the manufacturer's latest datasheet revision history to confirm active status and any recent pinout or electrical characteristic updates prior to final procurement.

Selection Notes

Select this component when designing systems requiring bidirectional data flow between different logic voltage domains. The HCT series compatibility makes it suitable for interfacing older TTL components with modern CMOS logic. Consider the 20 ns propagation delay and ±6 mA drive capability for signal integrity requirements. Verify that the 14-pin SOIC package dimensions align with your assembly constraints and thermal management needs.

Part Context

This component belongs to the Texas Instruments CD74HCT family of high-speed CMOS logic devices. The family is characterized by its ability to interface directly with TTL logic standards while offering improved speed and lower power consumption compared to standard HC series parts. The CD74HCT243 specifically addresses the need for robust, multi-channel bus interfacing in complex digital systems.

Replacement Considerations

Publicly confirmed substitute part numbers include CD74HC243MTE4 and CD74HCT243M. Verify functional equivalence regarding pinout and electrical specifications before substitution.