CD74FCT646TM

Overview

The CD74FCT646TM is an octal registered bus transceiver manufactured by Harris Corporation, belonging to the FCT logic series. It features a single functional unit with eight bits per element and non-inverting true output polarity. The device utilizes CMOS technology and provides three-state outputs for effective bus management. It operates within a supply voltage range of 4.75 V to 5.25 V and supports a wide operating temperature range from -40°C to +85°C. The component is housed in a 24-pin Small Outline (SOIC) surface-mount package.

Feature Summary

• Octal Registered Bus Transceiver functionality with direction control
• Three-state outputs for bidirectional data transmission
• CMOS construction ensuring low power consumption

Applications

• High-speed data bus interfaces
• Memory-to-memory transfers
• Microprocessor-based systems

Procurement Notes

Verify the manufacturer origin carefully, as Texas Instruments acquired Harris Semiconductor's logic assets. Confirm that the specific suffix 'TM' corresponds to the SOIC-24 package variant rather than other packaging options like TSSOP or SOIC-EP. Ensure compliance requirements are met, as older Harris production runs may not adhere to current RoHS standards.

Selection Notes

Select this component when an octal width with internal registration is required for synchronous bus operations. The FCT series offers speed comparable to LS-TTL but with CMOS power characteristics. Verify that the 24-pin SOIC footprint fits the PCB layout constraints and that the 5V logic levels match the system interface requirements.

Part Context

This part belongs to the Harris FCT (Fast CMOS Technology) family, designed to bridge the performance gap between standard TTL and CMOS logic. The 646 designation specifically identifies the octal registered transceiver topology within this portfolio, distinct from unregistered variants or different bit-width configurations.