SN74CBT6800CPW

Overview

The SN74CBT6800CPW is a 10-bit TTL-compatible FET bus switch in a TSSOP-24 package. It operates with a supply voltage (VCC) ranging from 4 V to 5.5 V and supports data I/O levels from 0 V to 5.5 V. The device features low ON-state resistance (ron), typically 3 Ω at VCC = 4.5 V, and bidirectional data flow with near-zero propagation delay (tpd). It includes active undershoot protection on A and B ports up to −2 V and precharges the B port via a user-selectable bias voltage (BIASV) to minimize live-insertion noise.

Feature Summary

• Active undershoot-protection circuitry on A and B ports ensures proper OFF state during undershoot events down to −2 V.
• B-port outputs are precharged by a user-selectable bias voltage (BIASV) to minimize signal distortion during live insertion and hot-plugging.
• Supports partial-power-down mode operation using Ioff feature to prevent damaging backflow current when powered down.
• Low input/output capacitance minimizes loading and signal distortion for high-speed applications.

Applications

• PCI interface
• Memory interleaving
• Bus isolation
• Low-distortion signal gating

Procurement Notes

Verify the specific ordering suffix 'PW' corresponds to the TSSOP-24 tube package configuration. Confirm that the C-grade temperature range (-40°C to +85°C) meets system requirements. Ensure the BIASV pin is properly connected to the desired bias level or ground as per the application design. Check for any recent Product Change Notifications regarding this part number.

Selection Notes

Select this component for applications requiring 10-bit wide bus switching with low signal distortion. The single ON control input simplifies logic compared to multi-control devices. Consider the BIASV pin functionality if live insertion or hot-plugging support is required. Verify that the 4 V to 5.5 V operating range aligns with the system power supply.

Part Context

This device belongs to the Texas Instruments Widebus family of high-speed FET bus switches. It is designed for minimal propagation delay and low ON-state resistance. The SN74CBT6800C variant specifically offers enhanced undershoot protection and bias voltage precharging capabilities compared to standard bus switches.

Replacement Considerations

Public confirmed substitute part numbers: SN74CBT6800CDW, SN74CBT6800CDB, SN74CBT6800CDBR, SN74CBT6800CDBQR, SN74CBT6800CDGVR, SN74CBT6800CDWR, SN74CBT6800CPWR, SN74CBT6800CPWRG4.

FAQ

How does the BIASV pin function?

The BIASV pin allows the user to select a bias voltage that precharges the B port through an equivalent 10-kΩ resistor when the switch is OFF or powered down. This minimizes glitching effects during card insertion or removal.

What is the purpose of the Ioff feature?

The Ioff feature ensures that damaging current will not backflow through the device when it is powered down (VCC = 0 V), supporting partial-power-down mode operation.