SN74ALS645A-1NS

Buffers, Drivers, Receivers, Transceivers Overview

The SN74ALS645A-1NS is an octal bus transceiver with 3-state outputs manufactured by Texas Instruments. It operates within a supply voltage range of 4.5 V to 5.5 V and supports a low-level output current (IOL) of up to 48 mA when VCC is between 4.75 V and 5.25 V. The device features a propagation delay of 10 ns maximum and functions over an operating temperature range of 0°C to 70°C. It utilizes a standard plastic 20-pin DIP package.

Buffers, Drivers, Receivers, Transceivers Feature Summary

• Bidirectional data transmission between A and B buses controlled by DIR input
• High-drive capability with increased IOL for the -1 version
• Three-state outputs allowing effective bus isolation via OE input

Buffers, Drivers, Receivers, Transceivers Applications

• Asynchronous two-way communication between data buses
• Bus-oriented memory and logic systems
• Clock drivers and bus transceivers

Buffers, Drivers, Receivers, Transceivers Procurement Notes

Verify that the ordering suffix 'N' corresponds to the PDIP-20 package configuration. Confirm the '-1' designation indicates the specific 48 mA low-level output current rating, which applies only when VCC is maintained between 4.75 V and 5.25 V. Ensure compatibility with TTL input levels as specified in the datasheet electrical characteristics.

Buffers, Drivers, Receivers, Transceivers Selection Notes

Select this component for applications requiring high-density octal bus interfacing with true logic functionality. The -1 variant provides enhanced drive strength compared to standard versions, suitable for driving heavier loads on bidirectional buses. Verify that the required operating temperature range aligns with the commercial 0°C to 70°C specification provided for the SN74 series.

Buffers, Drivers, Receivers, Transceivers Part Context

This part belongs to the SN54ALS645A/SN74ALS645A family of octal bus transceivers. It is designed for asynchronous communication and offers 3-state outputs. The device is available in multiple package options including plastic small-outline, ceramic chip carriers, and standard plastic DIPs. The SN74 series is characterized for commercial temperature ranges.

Buffers, Drivers, Receivers, Transceivers Replacement Considerations

SN74ALS645AN

Buffers, Drivers, Receivers, Transceivers FAQ

What is the specific function of the '-1' suffix in the model number?

The '-1' version increases the recommended maximum low-level output current (IOL) to 48 mA, but this rating applies only if VCC is between 4.75 V and 5.25 V.

How does the device control data direction?

Data transmission direction from the A bus to the B bus or vice versa is determined by the level at the direction-control (DIR) input.