CD74HC243EE4

Overview

The CD74HC243EE4 is a quad bus transceiver with three-state outputs manufactured by Texas Instruments. It operates within a supply voltage range of 2 V to 6 V and supports an operating temperature range from -55°C to +125°C. The device features buffered inputs and provides high-drive-current outputs capable of driving 15 LSTTL loads. Typical propagation delay is 7 ns at VCC = 5 V, CL = 15 pF, TA = 25°C. It is housed in a 14-pin PDIP package.

Feature Summary

• Quad bidirectional noninverting buffers designed for two-way asynchronous communication between data buses
• Three-state outputs controlled by OEA and OEB inputs to manage direction and high-impedance states
• High noise immunity with input levels defined as 30% of VCC at VCC = 5V
• Significant power reduction compared to LSTTL logic ICs while maintaining comparable speeds

Applications

• Two-way asynchronous communication between data buses
• Driving large bus capacitances with high-drive-current outputs
• Interface applications requiring buffered inputs and three-state control

Procurement Notes

Verify the specific ordering suffix EE4 corresponds to the PDIP (N) package configuration and NIPDAU lead finish as listed in the orderable addendum. Confirm RoHS compliance status and ensure the procurement channel sources from authorized distributors to guarantee authenticity. Check for any recent documentation updates or revision history changes that may affect design-in parameters.

Selection Notes

Select this component when designing systems requiring bidirectional data transfer with high-speed operation and low power consumption. The HC series offers wide voltage flexibility from 2 V to 6 V, suitable for various CMOS logic environments. Ensure the application does not require HCT input compatibility, which necessitates the CD74HCT243 variant instead. Verify thermal management requirements against the junction-to-ambient thermal resistance specifications.

Part Context

This part belongs to the CDx4HC243 family of high-speed CMOS logic devices. It serves as a catalog version of the military-grade CD54HC243. The device integrates four independent channels, each capable of bidirectional data flow controlled by separate output-enable inputs. It is designed to replace older LSTTL solutions in modern low-power digital designs.

Replacement Considerations

CD74HC243E is the direct equivalent without the environmental suffix. CD74HCT243E is required if LSTTL input compatibility is necessary. CD54HC243F is the military-grade alternative.