MC74ACT646NG

Overview

The MC74ACT646NG is an octal registered bus transceiver with 3-state outputs in a 24-lead SOIC package. It operates at a supply voltage of 4.5 V to 5.5 V and features TTL-compatible inputs. The device provides independent registers for A and B buses, enabling multiplexed real-time and stored data transfers. Propagation delay from clock to bus is typically 12.0 ns at 5.0 V, while bus-to-bus delay is typically 8.5 ns. Outputs source and sink up to 24 mA.

Feature Summary

• Independent registers for A and B buses allow multiplexed transmission of data directly from the input bus or internal storage registers.
• TTL-compatible inputs ensure compatibility with standard logic families.
• Outputs provide 3-state capability with high drive strength of 24 mA.
• Supports both true and inverting data paths for flexible system integration.

Applications

• Multiplexed transmission of registered and real-time data
• Octal bus-oriented architectures requiring storage and transfer capabilities
• Systems utilizing 3-state output isolation

Procurement Notes

Verify that the specific suffix 'NG' corresponds to the standard lead-free SOIC-24 configuration documented in official onsemi ordering lists. Confirm RoHS compliance status through current manufacturer documentation. Ensure the procurement channel sources genuine components matching the MC74ACT646DWG specification sheet.

Selection Notes

Select this component when an octal transceiver with integrated storage is required for bidirectional data flow. The ACT series ensures TTL input compatibility while maintaining CMOS output levels. Verify that the 24 mA output drive meets load requirements and that the 5.0 V operating range aligns with the system power supply.

Part Context

This device belongs to the MC74AC/ACT646 family of octal transceivers/register circuits. It shares functional similarities with other registered bus transceivers but is distinguished by its specific ACT logic family characteristics, including TTL-compatible inputs and defined propagation delays for 5.0 V operation.

Replacement Considerations

MC74ACT646DWG is a confirmed equivalent part number within the same product line offering identical functionality and pinout.

FAQ

How does the device handle data transfer between buses?

It supports multiplexed transmission, allowing data to be transferred either directly from the input bus (real-time) or from the internal storage registers based on control signal states.

What are the input voltage compatibility specifications?

The MC74ACT646 features TTL-compatible inputs, ensuring proper logic level recognition when interfacing with standard TTL logic families at 5.0 V operation.