MC74F646DW

Overview

The MC74F646DW is an octal bus transceiver from the onsemi 74F logic series, housed in a 24-pin SOIC package. It features non-inverting data paths with three-state outputs for bidirectional communication. The device operates within a supply voltage range of 4.5 V to 5.5 V and supports a propagation delay of 18 ns. It provides high drive capability with output currents of ±24 mA and functions reliably across an industrial temperature range of -40°C to +85°C.

Feature Summary

• Octal configuration providing eight independent non-inverting data channels for parallel bus interfacing
• Three-state outputs enable direct connection to system buses without additional buffering hardware
• High current drive capability ensures signal integrity over moderate trace lengths
• CMOS input structure compatible with standard TTL logic levels

Applications

• Bidirectional data transmission between microprocessors and memory modules
• I/O port expansion in embedded control systems
• Bus-oriented memory and switch interfacing applications
• Digital signal routing in industrial automation equipment

Procurement Notes

Verify component authenticity through authorized distributors due to potential availability of refurbished units. Confirm RoHS compliance status as original specifications may vary by production date. Check moisture sensitivity level handling requirements during storage and assembly. Validate pinout compatibility with target PCB footprint before integration into new designs.

Selection Notes

Select this component when high-speed octal transfer is required within a 5V logic environment. Consider alternative AC or ACT series variants if lower power consumption or wider voltage ranges are necessary. Ensure thermal management strategies account for the SOIC-24 package limitations in dense layouts. Verify that the 18 ns delay meets timing constraints for the specific bus architecture.

Part Context

This part belongs to the 74F family, known for fast switching speeds compared to standard 74LS counterparts. It serves as a registered bus transceiver, often used in legacy computer architectures and industrial controllers. The SOIC-24 package offers a compact surface-mount solution suitable for automated assembly processes.

Replacement Considerations

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