SN74HC645NSRE4

Buffers, Drivers, Receivers, Transceivers Overview

The SN74HC645NSRE4 is an octal bus transceiver from the Texas Instruments HC logic series, housed in a 20-pin NS (SOIC) surface-mount package. It provides bidirectional data transmission between two 8-bit buses with non-inverting logic and three-state outputs. The device operates within a supply voltage range of 2 V to 6 V and supports an operating temperature range of -40 °C to +85 °C. Key electrical characteristics include a maximum propagation delay of 26 ns at 4.5 V with a 50 pF load, output drive capabilities up to ±6 mA at 5 V, and a maximum quiescent current of 80 µA.

Buffers, Drivers, Receivers, Transceivers Feature Summary

• Provides asynchronous two-way communication between data buses via direction control
• Features high-current three-state outputs capable of driving LSTTL loads
• Includes an output-enable input for effective bus isolation

Buffers, Drivers, Receivers, Transceivers Applications

• Asynchronous two-way communication between data buses
• Bus-oriented memory and register implementations
• Input/output expansion using synchronous and asynchronous devices

Buffers, Drivers, Receivers, Transceivers Procurement Notes

Verify that the ordering suffix 'E4' corresponds to the specific tape-and-reel packaging configuration required for automated assembly processes. Confirm that the component meets RoHS standards and lead finish specifications as defined in the manufacturer's latest package addendum. Ensure the selected variant matches the required thermal and moisture sensitivity ratings for the intended manufacturing environment.

Buffers, Drivers, Receivers, Transceivers Selection Notes

Select this component when designing systems requiring wide voltage operation between 2 V and 6 V. The HC series offers low power consumption suitable for battery-operated applications. Verify that the SOIC-20 package dimensions align with the printed circuit board layout constraints and that the thermal impedance characteristics are adequate for the expected ambient operating conditions.

Buffers, Drivers, Receivers, Transceivers Part Context

This device belongs to the SN74HC645 family of octal bus transceivers manufactured by Texas Instruments. It is part of the broader 74HC logic family, which utilizes CMOS technology to provide high-speed operation with low static power dissipation. The component serves as a standard interface solution for connecting microprocessors, memory modules, and peripheral devices in digital logic circuits.

Buffers, Drivers, Receivers, Transceivers Replacement Considerations

SN74HC645N

Buffers, Drivers, Receivers, Transceivers FAQ

How does the DIR input control data flow?

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

What is the function of the OE input?

The output-enable (OE) input controls the state of the outputs. When OE is high, the outputs are disabled, effectively isolating the buses regardless of the DIR input level.