SN74CBT16811CDGGR

Overview

The SN74CBT16811CDGGR is a high-speed TTL-compatible FET bus switch from the Widebus family, organized as two independent 12-bit switches or one 24-bit switch. It operates within a VCC range of 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) with typical values of 3 Ω at VI=0 and 8 Ω at VI=2.4 V. 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). Control inputs are compatible with TTL or 5-V/3.3-V CMOS outputs.

Feature Summary

• Active undershoot-protection circuitry on A and B ports ensures proper OFF state during signal glitches.
• B-port precharging via BIASV minimizes live-insertion noise and signal distortion.
• Supports partial-power-down mode using Ioff feature to prevent damaging backflow current.
• Bidirectional data flow with near-zero propagation delay characteristics.

Applications

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

Procurement Notes

Verify the specific ordering suffix 'DGGR' corresponds to the TSSOP-56 tape-and-reel package configuration. Confirm that the C-grade temperature rating (-40°C to 85°C) aligns with system requirements. Ensure control inputs are tied to VCC or GND to maintain proper operation and avoid floating states.

Selection Notes

Select this component for applications requiring bidirectional switching between 4-V and 5.5-V logic domains. The device is suitable where low capacitance and fast switching speeds are critical. Verify that the BIASV pin can be connected to an appropriate voltage level to match receiver input thresholds for optimal glitch reduction during insertion events.

Part Context

This part belongs to the SN74CBT16811C series within Texas Instruments' Widebus family. It is designed as a high-performance alternative to standard bus switches, offering enhanced protection features like undershoot clamping and configurable biasing. The device integrates two 12-bit channels into a single 56-pin TSSOP package.

Replacement Considerations

SN74CBT16811CDGG is the tube version of the same functional device in the DGG package.

FAQ

How does the device handle live insertion?

The B port is precharged to the BIASV voltage when the switch is off, minimizing live-insertion noise by preventing glitches from crossing receiver input thresholds.

What is the function of the Ioff feature?

The Ioff feature ensures that no damaging current flows through the device when it is powered down, providing isolation during partial-power-down operations.