SN74HC645NSR

Buffers, Drivers, Receivers, Transceivers Overview

The SN74HC645NSR is an octal bus transceiver from the Texas Instruments HC logic family, housed in a 20-pin SOIC package. It supports a wide operating voltage range of 2 V to 6 V and features high-current 3-state outputs capable of driving up to 15 LSTTL loads. The device provides asynchronous two-way communication between data buses with a typical propagation delay of 12 ns at 5 V. It consumes low power with a maximum static current of 80 µA and includes direction control (DIR) and output enable (OE) inputs for managing data flow and isolation.

Buffers, Drivers, Receivers, Transceivers Feature Summary

• Provides asynchronous bidirectional data transfer between A and B buses controlled by a DIR input
• Features high-current 3-state outputs designed to drive heavy loads such as LSTTL circuits
• Includes an OE input to isolate buses when the device is disabled
• Operates within a wide supply voltage range suitable for various system architectures

Buffers, Drivers, Receivers, Transceivers Applications

• Asynchronous two-way communication between data buses
• Memory-to-memory transfers
• Microprocessor decoding systems

Buffers, Drivers, Receivers, Transceivers Procurement Notes

Verify the specific ordering suffix against the manufacturer's latest Package Option Addendum to confirm active status and material specifications. Ensure the selected variant matches the required temperature range and packaging format for your assembly process. Cross-reference the datasheet revision date to validate electrical characteristics before finalizing component selection.

Buffers, Drivers, Receivers, Transceivers Selection Notes

Select this component for applications requiring wide voltage operation and high drive capability. The HC series offers compatibility with standard CMOS logic levels while providing sufficient current for interfacing with TTL loads. Consider the 20-pin SOIC footprint for surface-mount designs requiring eight-bit parallel data handling with independent direction control.

Buffers, Drivers, Receivers, Transceivers Part Context

This part belongs to the SN74HC645 family of octal bus transceivers. It is functionally equivalent to other variants in the series but differs in package type and manufacturing lot specifications. The NSR suffix indicates a tape-and-reel packaging configuration optimized for automated surface-mount assembly processes.

Buffers, Drivers, Receivers, Transceivers Replacement Considerations

SN74HC645DWR

Buffers, Drivers, Receivers, Transceivers FAQ

How does the DIR input affect data flow?

When DIR is low, data flows from the A bus to the B bus. When DIR is high, data flows from the B bus to the A bus.

What is the function of the OE input?

The OE (Output Enable) input disables the outputs when high, effectively isolating the buses from each other regardless of the DIR setting.