SN74ALS645A-1DWR

Buffers, Drivers, Receivers, Transceivers Overview

The SN74ALS645A-1DWR is an octal bus transceiver with 3-state outputs in a 20-pin SOIC package. It facilitates asynchronous two-way communication between data buses, transmitting data from the A bus to the B bus or vice versa based on the DIR input level. The -1 version features an increased recommended maximum IOL of 48 mA when VCC is between 4.75 V and 5.25 V. Operating voltage ranges from 4.5 V to 5.5 V, with a temperature range of 0°C to 70°C.

Buffers, Drivers, Receivers, Transceivers Feature Summary

• Bidirectional data transmission between A and B buses controlled by DIR input
• Three-state outputs allowing effective bus isolation via OE input
• -1 version supports increased low-level output current up to 48 mA

Buffers, Drivers, Receivers, Transceivers Applications

• Asynchronous two-way communication between data buses
• Bus-oriented memory and logic systems
• High-density circuit designs requiring bidirectional data flow

Buffers, Drivers, Receivers, Transceivers Procurement Notes

Verify the specific -1 suffix designation to confirm the device meets the required 48 mA low-level output current specification under valid supply voltage conditions. Ensure the SOIC-20 package type aligns with board layout constraints. Confirm RoHS compliance status for environmental requirements.

Buffers, Drivers, Receivers, Transceivers Selection Notes

Select this component for applications requiring high-speed bidirectional data transfer with enhanced drive capability. The ALS series offers faster switching speeds compared to standard LS logic. Consider the -1 variant specifically if higher sink current is necessary for driving heavy loads on the data bus.

Buffers, Drivers, Receivers, Transceivers Part Context

This part belongs to the Texas Instruments SN74ALS645A family of octal bus transceivers. It shares functional similarities with other devices in the 74ALS series but is distinguished by its specific pinout and enhanced output current characteristics in the -1 version. It serves as a critical interface component in digital systems managing parallel data paths.

Buffers, Drivers, Receivers, Transceivers Replacement Considerations

SN74ALS645ADWR (Standard version without -1 suffix)

Buffers, Drivers, Receivers, Transceivers FAQ

What distinguishes the SN74ALS645A-1DWR from the standard SN74ALS645ADWR?

The -1 version has an increased recommended maximum IOL of 48 mA when VCC is between 4.75 V and 5.25 V, whereas the standard version typically specifies lower current limits.

How does the device control data direction?

Data direction is determined by the DIR input level. A low level on DIR allows data to flow from the B bus to the A bus, while a high level directs data from the A bus to the B bus.