CD74HCT251E

Overview

The CD74HCT251E is a high-speed CMOS logic device manufactured by Harris Corporation, functioning as an 8-input multiplexer with three-state outputs. It operates within a supply voltage range of 2V to 6V and supports data rates up to 38MHz. The component utilizes a 16-pin DIP package and is designed for operation across an extended temperature range of -55°C to 125°C. It belongs to the 74HC series, ensuring compatibility with standard CMOS logic interfaces while providing robust signal switching capabilities.

Feature Summary

• Provides eight selectable input lines routed to a single output through address selection
• Features three-state output capability allowing direct connection to bus structures
• Constructed using high-speed CMOS technology for low power consumption and fast switching

Applications

• Data routing in digital communication systems
• Address decoding in microprocessor-based designs
• Signal selection in test and measurement equipment

Procurement Notes

Verify the manufacturer designation carefully, as Harris Corporation was acquired by Renesas Electronics. Confirm that the specific part number corresponds to the original Harris production run rather than subsequent Renesas releases. Ensure the package type matches the required 16-pin DIP configuration for your board layout. Check for any RoHS compliance markings if environmental regulations apply to your assembly process.

Selection Notes

Select this component when an 8-to-1 multiplexing function with tri-state outputs is required in a CMOS environment. The HCT suffix indicates TTL-compatible inputs, facilitating interface with legacy logic families. Consider the operating temperature range and supply voltage requirements to ensure compatibility with the target system's power rails and thermal conditions.

Part Context

This device is part of the broader 74HC logic family, which offers high-speed performance comparable to LS-TTL but with lower power dissipation. The CD prefix typically denotes commercial grade devices, distinguishing them from military-grade counterparts like the CD54 series. It serves as a fundamental building block for complex digital logic circuits requiring data path management.

Replacement Considerations

Compatible substitutes include the CD74HC251M and CD74HCT251ME4. Verify pinout compatibility and electrical specifications before substitution. Note that some equivalents may have different packaging options or slight variations in propagation delay characteristics.