SN74ALS642AN

Buffers, Drivers, Receivers, Transceivers Overview

The SN74ALS642AN is an octal bus transceiver from the Texas Instruments ALS logic family, housed in a standard plastic 300-mil DIP-20 package. It facilitates asynchronous two-way communication between data buses by transmitting data from the A bus to the B bus or vice versa, determined by the direction-control (DIR) input level. The device features an output-enable (OE) input that isolates the buses when active. Designed for operation within a supply voltage range of 4.5 V to 5.5 V and an operating temperature range of 0°C to 70°C, it provides inverting logic functionality.

Buffers, Drivers, Receivers, Transceivers Feature Summary

• Bidirectional octal bus transceiver architecture supporting asynchronous two-way data communication
• Direction control via DIR input determines signal flow between A and B buses
• Output isolation capability provided by OE input to effectively disconnect buses
• Inverting logic configuration within the high-density ALS series

Buffers, Drivers, Receivers, Transceivers Applications

• Asynchronous two-way communication between data buses
• I/O buffering and interface circuits
• Memory-to-memory transfers
• Bus-oriented architectures requiring bidirectional data transfer

Buffers, Drivers, Receivers, Transceivers Procurement Notes

Verify the specific ordering suffix 'AN' corresponds to the PDIP-20 package variant. Confirm RoHS compliance status through official documentation as requirements may vary by production batch. Ensure the application environment remains within the specified 0°C to 70°C operating temperature range and 4.5 V to 5.5 V supply voltage limits to maintain guaranteed performance characteristics.

Buffers, Drivers, Receivers, Transceivers Selection Notes

Select this component when inverting logic is required for bidirectional data transfer applications. The ALS series offers improved speed and power consumption compared to standard LS logic. Verify that the 20-pin DIP package fits the target PCB layout constraints. Consider the -1 version if higher low-level output current drive is necessary for specific load conditions.

Buffers, Drivers, Receivers, Transceivers Part Context

This device belongs to the SN74ALS64xA family of octal bus transceivers. It shares functional similarities with the non-inverting SN74ALS641A but differs in logic polarity. The ALS technology provides faster switching speeds than standard TTL families while maintaining lower power dissipation. It is part of the broader 74-series logic ecosystem designed for general-purpose digital applications.

Buffers, Drivers, Receivers, Transceivers Replacement Considerations

SN74ALS641A (Non-inverting equivalent)

Buffers, Drivers, Receivers, Transceivers FAQ

What is the logic polarity of the SN74ALS642AN?

The SN74ALS642AN provides inverting logic, meaning the output signals are inverted relative to the inputs.

How does the device isolate the buses?

The output-enable (OE) input disables the device when asserted, effectively isolating the A and B buses from each other.