SN74ALS642A-1N

Buffers, Drivers, Receivers, Transceivers Overview

The SN74ALS642A-1N is an octal bus transceiver in the ALS logic series, housed in a 20-pin PDIP package. It provides bidirectional asynchronous communication between data buses with inverting logic. The device operates within a supply voltage range of 4.5 V to 5.5 V and supports an operating temperature range of 0°C to 70°C. The -1 suffix indicates an increased recommended maximum low-level output current (IOL) of 48 mA when VCC is between 4.75 V and 5.25 V. Propagation delays for A/B to B/A transitions range from 10 ns to 30 ns.

Buffers, Drivers, Receivers, Transceivers Feature Summary

• Bidirectional data transfer capability controlled by a direction input
• Inverting logic function for signal transmission
• High-drive output capability with 48 mA low-level sink current in the -1 version

Buffers, Drivers, Receivers, Transceivers Applications

• Asynchronous two-way communication between data buses
• Bus-oriented memory and register systems
• Control signals driving multiple loads

Buffers, Drivers, Receivers, Transceivers Procurement Notes

Verify the specific ordering suffix '-1' to confirm the enhanced 48 mA low-level output current specification, which applies only when VCC is maintained between 4.75 V and 5.25 V. Ensure the procurement matches the 'N' designation for the standard plastic DIP package. Confirm RoHS compliance status as indicated in the manufacturer's packaging addendum.

Buffers, Drivers, Receivers, Transceivers Selection Notes

Select this component when inverting logic is required for octal bus interfacing. The -1 variant offers higher drive strength compared to standard versions, suitable for applications requiring greater low-level output current. Verify that the system operates within the specified 0°C to 70°C temperature range and utilizes TTL-compatible input levels.

Buffers, Drivers, Receivers, Transceivers Part Context

This device belongs to the Texas Instruments SN74ALS64x family of octal bus transceivers. It shares functional similarities with the non-inverting SN74ALS641A but differs in its inverting logic characteristic. The -1 suffix specifically denotes the enhanced current drive capability found in this particular revision of the ALS series.

Buffers, Drivers, Receivers, Transceivers Replacement Considerations

SN74ALS642A-1DW

Buffers, Drivers, Receivers, Transceivers FAQ

What is the difference between the SN74ALS642A and SN74ALS642A-1?

The -1 version features an increased recommended maximum low-level output current (IOL) of 48 mA, provided the supply voltage remains between 4.75 V and 5.25 V.

How does the direction control input affect data flow?

When the DIR input is high, data flows from the A bus to the B bus. When DIR is low, data flows from the B bus to the A bus.