CD74ACT646M

Overview

The CD74ACT646M is an octal registered bus transceiver from the ACT logic series, manufactured by Harris Corporation. It features a 24-pin SOIC package and operates with a supply voltage range of 4.5 V to 5.5 V. The device provides non-inverting data transmission with TTL input levels and CMOS output levels. Key electrical characteristics include a maximum propagation delay of 12.5 ns at 5 V and output drive currents of ±24 mA. It supports bidirectional data flow controlled by direction inputs and includes a select input for multiplexed transmission of registered or real-time data.

Feature Summary

• Octal registered bus transceiver architecture supporting bidirectional data transfer
• Direction control and select input for multiplexed transmission of registered or real-time data
• TTL-compatible input levels with high-current CMOS outputs
• Three-state outputs for efficient bus interfacing

Applications

• High-speed data bus systems requiring registered buffering
• Multiplexed data transmission interfaces
• Bidirectional memory bus architectures
• Industrial control systems with TTL/CMOS mixed-level signaling

Procurement Notes

Verify manufacturer origin as Harris Corporation, noting that Texas Instruments also produces compatible variants in this family. Confirm package type is SOIC-24 and check RoHS compliance status, as older Harris-produced units may not meet current environmental standards. Ensure operating temperature range matches application requirements, typically -55°C to +125°C for this series.

Selection Notes

Select this component when high-speed registered bus transfer is required with TTL input compatibility. The ACT series offers faster performance than standard AC/HCT families while maintaining CMOS output drive strength. Consider the M96 suffix variant if reel packaging is needed instead of tube. Verify that the 24 mA output current capability meets load requirements for the specific bus topology.

Part Context

This part belongs to the CD74ACT646 family of octal bus transceivers. Harris Corporation was a significant producer of this logic family before its acquisition by Texas Instruments. The device serves as a registered buffer for bidirectional data buses, providing storage and direction control capabilities essential for complex digital systems.

Replacement Considerations

CD74ACT646M96 (Texas Instruments) offers identical functionality with reel packaging. CD74AC646M provides similar performance without the registered feature. CD74HCT646M is available for lower voltage applications but with slower speed.