MC74AC646DWR2

Overview

The MC74AC646DWR2 is an octal bus transceiver and register manufactured by onsemi, belonging to the 74AC logic series. It features non-inverting data paths with three-state outputs capable of sourcing and sinking 24 mA. The device operates within a supply voltage range of 2 V to 6 V and supports a maximum propagation delay of 16.5 ns. Designed for surface-mount applications, it utilizes a 24-SOIC package and functions reliably across an industrial temperature range of -40°C to +85°C.

Feature Summary

• Provides multiplexed transmission of data directly from input buses or internal storage registers via D-type flip-flops.
• Features independent registers for A and B buses allowing choice between true and inverting data paths.
• Delivers high-drive three-state outputs suitable for driving bus lines and memory interfaces.

Applications

• High-speed data acquisition systems requiring registered bus interfacing
• Memory mapping and buffer applications in embedded controllers
• Industrial control networks utilizing CMOS logic standards

Procurement Notes

Verify the exact suffix 'DWR2' against official onsemi documentation, as standard listings often cite 'MC74AC646DWR2G'. Confirm RoHS compliance status and moisture sensitivity level (MSL) requirements for your assembly process. Ensure the SOIC-24 footprint matches your PCB design constraints before finalizing procurement orders.

Selection Notes

Select this component when an octal transceiver with integrated registration is required for 2V to 6V CMOS systems. It is appropriate for designs needing simultaneous data capture and transfer capabilities. Consider the 16.5 ns propagation delay and 24 mA drive strength for signal integrity analysis. Verify that the surface-mount package fits the available board space compared to through-hole alternatives.

Part Context

This part belongs to the widely adopted 74AC family of high-speed CMOS logic devices. It serves as a registered version of the standard 74AC646 transceiver, adding storage functionality for synchronized data handling. The device complements other onsemi logic products like the MC74ACT646DW, offering similar functionality with AC speed characteristics rather than ACT TTL-compatible inputs.

Replacement Considerations

Public confirmed substitute part numbers include CD74ACT646M96 from Texas Instruments. Verify pin compatibility and electrical specifications before substitution.