SN74LS642NSR

Buffers, Drivers, Receivers, Transceivers Overview

The SN74LS642NSR is an octal bus transceiver from the Texas Instruments SN74LS series. It features open-collector outputs and operates within a supply voltage range of 4.75 V to 5.25 V. The device supports a propagation delay of 15 ns and provides a low-level output current of 24 mA with a high-level output current of -15 mA. It is housed in a 20-pin SOIC package and functions across a temperature range of 0°C to +70°C.

Buffers, Drivers, Receivers, Transceivers Feature Summary

• Octal bus transceiver architecture providing bidirectional data transfer capability between two buses.
• Open-collector output configuration suitable for wired-OR applications and interfacing with varying logic levels.
• Low-power Schottky (LS) technology implementation ensuring reduced power consumption relative to standard TTL.

Buffers, Drivers, Receivers, Transceivers Applications

• Bidirectional data bus transmission systems
• Memory-to-memory or memory-to-I/O data transfers
• Bus-oriented architectures requiring open-collector termination

Buffers, Drivers, Receivers, Transceivers Procurement Notes

Verify that the specific application environment accommodates the open-collector output nature, which requires external pull-up resistors to function correctly as a logic high source. Confirm that the operating voltage remains strictly within the 4.75 V to 5.25 V limits to ensure signal integrity and prevent device damage. Ensure the design accounts for the 15 ns propagation delay characteristics when determining maximum system clock speeds.

Buffers, Drivers, Receivers, Transceivers Selection Notes

Select this component when an octal transceiver with open-collector outputs is required rather than the 3-state variants found in the SN74LS640 or SN74LS645 families. The LS series designation indicates a balance of speed and power dissipation appropriate for general-purpose digital logic applications. Verify that the 20-pin SOIC footprint matches the target PCB layout constraints.

Buffers, Drivers, Receivers, Transceivers Part Context

This part belongs to the SN54LS640 through SN54LS645 family of octal bus transceivers manufactured by Texas Instruments. While the SN74LS640 and SN74LS645 utilize 3-state outputs, the SN74LS642 specifically employs open-collector outputs. This distinction defines its electrical behavior and suitability for specific bus topologies compared to other members of the same logical family.

Buffers, Drivers, Receivers, Transceivers Replacement Considerations

SN74LS642N

Buffers, Drivers, Receivers, Transceivers FAQ

Does the SN74LS642NSR have 3-state outputs?

No, the SN74LS642NSR utilizes open-collector outputs. Devices such as the SN74LS640 or SN74LS645 provide 3-state outputs instead.

What is the recommended supply voltage range for this device?

The device must be operated within a supply voltage range of 4.75 V to 5.25 V.