SN74HC645DW

Buffers, Drivers, Receivers, Transceivers Overview

The SN74HC645DW is an octal bus transceiver from the Texas Instruments HC logic family, housed in a 20-pin SOIC package. It provides asynchronous two-way communication between data buses with non-inverting transmission controlled by a DIR input and isolation via an OE input. The device operates on a supply voltage range of 2 V to 6 V, featuring high-current 3-state outputs capable of driving up to 15 LSTTL loads. Electrical characteristics include a maximum propagation delay of 22 ns at 6 V, low power consumption with a maximum ICC of 80 µA, and output drive currents of ±6 mA at 5 V.

Buffers, Drivers, Receivers, Transceivers Feature Summary

• Octal bidirectional bus transceiver designed for asynchronous two-way communication between data buses
• Direction control (DIR) input determines data flow direction between A and B buses
• Output-enable (OE) input allows effective isolation of buses when disabled
• High-current 3-state outputs provide sufficient drive capability for multiple LSTTL loads

Buffers, Drivers, Receivers, Transceivers Applications

• Asynchronous two-way communication between data buses
• Bus-oriented memory and signal buffering
• Input/output buffering for microprocessor systems

Buffers, Drivers, Receivers, Transceivers Procurement Notes

Verify the specific ordering suffix against the manufacturer's current Package Option Addendum to confirm production status and availability. The SN74HC645DW tube version is listed as obsolete; ensure the selected variant matches the required packaging format and environmental compliance specifications such as RoHS status before procurement.

Buffers, Drivers, Receivers, Transceivers Selection Notes

Select this component for applications requiring wide operating voltage ranges from 2 V to 6 V. Ensure the design accommodates the specified thermal impedance of 58 °C/W for the DW package. Verify that input transition rise/fall times remain within recommended limits to maintain switching performance and prevent excessive power consumption during operation.

Buffers, Drivers, Receivers, Transceivers Part Context

This device belongs to the SN74HC645 series of octal bus transceivers manufactured by Texas Instruments. It is part of the broader HC logic family, which utilizes CMOS technology to achieve low power consumption while maintaining high-speed performance. The SN74HC645DW specifically denotes the standard catalog version packaged in a 20-lead Small Outline Integrated Circuit (SOIC) format.

Buffers, Drivers, Receivers, Transceivers Replacement Considerations

SN74HC645DWR

Buffers, Drivers, Receivers, Transceivers FAQ

How does the SN74HC645DW control data flow direction?

Data flow is determined by the level at the direction-control (DIR) input. A low level directs data from the B bus to the A bus, while a high level directs data from the A bus to the B bus.

What is the function of the OE input?

The output-enable (OE) input disables the device when set to a high level, effectively isolating the buses from each other regardless of the DIR input state.