SN74CBT3345CDW

Overview

The SN74CBT3345CDW is an octal FET bus switch manufactured by Texas Instruments, housed in a 20-pin SOIC (DW) package. It operates on a single supply voltage ranging from 4 V to 5.5 V and supports bidirectional data flow between A and B ports with near-zero propagation delay. The device features low ON-state resistance of 3 Ω typical and low input/output capacitance of 5.5 pF typical. It includes active undershoot protection up to -2 V, Ioff support for partial-power-down mode, and ESD protection rated at 2000-V human-body model.

Feature Summary

• Active undershoot-protection circuitry ensures proper OFF state during signal undershoot events up to -2 V
• Ioff feature prevents damaging backflow current when the device is powered down
• Bidirectional data flow with TTL-compatible control inputs driven by 5-V or 3.3-V CMOS outputs

Applications

• USB interface connections
• Memory interleaving circuits
• Bus isolation applications
• Low-distortion signal gating

Procurement Notes

Verify the specific ordering suffix 'DW' corresponds to the SOIC tube packaging configuration. Confirm that the RoHS status and lead finish match project requirements. Ensure the operating temperature range of -40°C to 85°C aligns with system thermal constraints. Cross-reference the moisture sensitivity level rating before assembly processing.

Selection Notes

Select this component for high-speed digital and analog applications requiring minimal signal distortion. The low ON-state resistance and capacitance make it suitable for maintaining signal integrity across wide buses. Verify that the control input voltage levels are compatible with the driving logic family. Consider the package size and pin count relative to available PCB real estate.

Part Context

This part belongs to the SN74CBT3345C series of high-speed TTL-compatible FET bus switches. It is designed to provide efficient switching capabilities for 8-bit data paths. The device integrates internal enable signals and protection features to enhance reliability in complex digital systems.

Replacement Considerations

SN74CBT3345CDWR is the tape-and-reel version of the same functional device in the DW package.

FAQ

How does the device handle undershoot events?

The SN74CBT3345CDW includes active undershoot-protection circuitry on the A and B ports that senses undershoot events up to -2 V and maintains the switch in the proper OFF state.

What is the function of the Ioff feature?

The Ioff feature ensures that damaging current will not backflow through the device when it is powered down, supporting partial-power-down mode operation.