SN74AS639DW

Buffers, Drivers, Receivers, Transceivers Overview

The SN74AS639DW is an octal bus transceiver from the Texas Instruments AS logic series, housed in a 20-pin Small-Outline (SOIC) package. It facilitates asynchronous two-way communication between open-collector and 3-state buses. The device features true logic polarity with A-bus outputs configured as open collector and B-bus outputs as 3-state. Recommended operating conditions specify a supply voltage range of 4.5 V to 5.5 V and an operating temperature range of 0°C to 70°C.

Buffers, Drivers, Receivers, Transceivers Feature Summary

• Bidirectional data transmission capability between open-collector and 3-state buses controlled by direction input
• Mixed output architecture providing open-collector ports on one bus and 3-state ports on the other
• True logic polarity for non-inverting signal transfer

Buffers, Drivers, Receivers, Transceivers Applications

• Asynchronous communication interfaces between mixed logic families
• Data bus buffering and isolation in digital systems
• Interfacing open-collector devices with standard 3-state logic circuits

Buffers, Drivers, Receivers, Transceivers Procurement Notes

Verify component authenticity through official manufacturer channels or authorized distributors. Confirm the specific SOIC-20 package variant matches design requirements. Review the latest datasheet revision for any updates to electrical characteristics or mechanical dimensions before finalizing procurement specifications.

Buffers, Drivers, Receivers, Transceivers Selection Notes

Select this component when bidirectional data flow is required between buses with different output drive capabilities. The open-collector A-bus allows wired-AND configurations, while the 3-state B-bus supports high-speed multiplexing. Ensure system voltage levels remain within the specified 4.5 V to 5.5 V range for reliable operation.

Buffers, Drivers, Receivers, Transceivers Part Context

This device belongs to the SN74AS family of high-speed Schottky logic components. It serves as a bridge between different bus standards, enabling flexible system architectures. The DW suffix indicates the plastic small-outline package format suitable for surface-mount assembly techniques.

Buffers, Drivers, Receivers, Transceivers Replacement Considerations

SN74ALS639ADW offers similar functionality with lower power consumption but reduced speed. SN74LS646 provides comparable 3-state performance without the open-collector feature.