SN74HCT645PWRE4

Buffers, Drivers, Receivers, Transceivers Overview

The SN74HCT645PWRE4 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 an operating temperature range of -40°C to 85°C. The device features high-current outputs capable of driving up to 15 LSTTL loads, with typical output drive currents of ±6 mA at 5 V. Input characteristics include TTL-voltage compatibility and low input current of 1 µA maximum. Propagation delay is typically 14 ns at 5.5 V with a 50 pF load. The component utilizes a 20-pin TSSOP package.

Buffers, Drivers, Receivers, Transceivers Feature Summary

• Provides asynchronous two-way communication between data buses via direction control
• Features high-current 3-state outputs for driving heavy loads
• Ensures electrical isolation when the output-enable input is deactivated

Buffers, Drivers, Receivers, Transceivers Applications

• Asynchronous two-way communication between data buses
• System memory address decoding
• Clock drivers

Buffers, Drivers, Receivers, Transceivers Procurement Notes

Verify that the ordering suffix RE4 corresponds to the specific tape-and-reel packaging configuration required for automated assembly processes. Confirm the moisture sensitivity level rating aligns with the facility's floor life requirements before soldering. Ensure the lead finish specification meets the board assembly standards. Cross-reference the RoHS compliance status with environmental regulations applicable to the final product deployment region.

Buffers, Drivers, Receivers, Transceivers Selection Notes

Select this component when TTL-compatible inputs are necessary for interfacing with legacy logic families while maintaining CMOS power efficiency. The HCT series ensures direct compatibility with standard TTL voltage levels without requiring external pull-up resistors. Consider the propagation delay specifications relative to the system clock speed to ensure signal integrity across the bidirectional bus architecture.

Buffers, Drivers, Receivers, Transceivers Part Context

This device belongs to the SN74HCT645 family of octal bus transceivers. It shares functional similarities with other bidirectional transceivers but is distinguished by its HCT logic technology, which provides TTL-compatible input thresholds. The PW package variant indicates a thin-shrink small-outline design suitable for space-constrained printed circuit board layouts.

Buffers, Drivers, Receivers, Transceivers Replacement Considerations

SN74HCT645PWR

Buffers, Drivers, Receivers, Transceivers FAQ

How does the DIR input determine 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 disables the device when high, effectively isolating the buses from each other regardless of the direction control state.