SN74ALS621A-1DW

Buffers, Drivers, Receivers, Transceivers Overview

The SN74ALS621A-1DW is an octal bus transceiver from the Texas Instruments ALS logic family, housed in a 20-pin SOIC (DW) package. It features open-collector true outputs and operates within a supply voltage range of 4.5 V to 5.5 V. The device supports asynchronous two-way communication between data buses with dual output-enable inputs (OEAB and OEBA). Recommended operating conditions specify a low-level output current of 48 mA for the -1 version when VCC is between 4.75 V and 5.25 V. Switching characteristics indicate maximum propagation delays of 33 ns from A to B and 20 ns from B to A under standard test conditions.

Buffers, Drivers, Receivers, Transceivers Feature Summary

• Provides asynchronous two-way communication capability between data buses using dual independent control inputs.
• Features open-collector outputs that reinforce input signals to maintain bus states during simultaneous enablement.
• Includes local bus-latch functionality allowing data storage by simultaneously enabling both direction controls.

Buffers, Drivers, Receivers, Transceivers Applications

• Asynchronous two-way communication between data buses
• Bus-oriented memory and register implementations
• Local bus-latch applications

Buffers, Drivers, Receivers, Transceivers Procurement Notes

Verify the specific ordering suffix '-1' to confirm the increased recommended maximum low-level output current specification. Ensure the supply voltage remains within the 4.75 V to 5.25 V range if utilizing the enhanced 48 mA drive capability. Confirm the open-collector output type aligns with the external pull-up requirements of the target circuit design.

Buffers, Drivers, Receivers, Transceivers Selection Notes

Select this component for designs requiring high-drive open-collector outputs on bidirectional buses. The -1 designation indicates a higher current rating compared to standard versions. Verify compatibility with TTL input levels and ensure the application does not require three-state or inverting logic functions.

Buffers, Drivers, Receivers, Transceivers Part Context

This device belongs to the Texas Instruments SN74ALS621A series of octal bus transceivers. It is part of the Advanced Low-Power Schottky (ALS) logic family, designed for reduced power consumption while maintaining high-speed performance. The DW package variant utilizes a plastic small-outline form factor suitable for surface-mount assembly.

Buffers, Drivers, Receivers, Transceivers Replacement Considerations

Public confirmed substitute part numbers: None identified.