SN74CBT6845CDGVR

Overview

The SN74CBT6845CDGVR is an 8-bit FET bus switch from the SN74CBT6845C series, manufactured by Texas Instruments. It operates within a VCC range of 4 V to 5.5 V and supports bidirectional data flow with near-zero propagation delay. The device features active undershoot protection on A and B ports up to -2 V and precharges B-port outputs via a user-selectable bias voltage (BIASV) to minimize live-insertion noise. It offers low ON-state resistance (3 Ω typical), low input/output capacitance (5.5 pF typical), and supports partial-power-down mode through Ioff isolation. Packaged in a 20-pin TVSOP (DGV).

Feature Summary

• Active undershoot-protection circuitry ensures proper OFF state during undershoot events up to -2 V.
• B-port precharging minimizes signal distortion and live-insertion noise during hot-plugging.
• Supports partial-power-down applications with Ioff feature preventing backflow current when powered down.
• Low ON-state resistance and low capacitance characteristics minimize loading and signal distortion.

Applications

• PCI interface support including PCI hot plug operations.
• Memory interleaving and bus isolation tasks.
• Low-distortion signal gating for digital and analog applications.

Procurement Notes

Verify the specific DGV package designation and tape-and-reel carrier configuration against the official TI ordering information. Confirm that the BIASV pin connection matches the target receiver input threshold requirements for optimal glitch reduction during insertion or removal events.

Selection Notes

Select this component for high-speed TTL-compatible applications requiring minimal propagation delay and robust undershoot protection. Ensure the control inputs are driven by compatible TTL or CMOS levels and that the OE pin is properly biased to maintain high-impedance states during power transitions.

Part Context

This part belongs to the SN74CBT6845C family of high-speed FET bus switches designed for low-voltage signaling environments. It provides 8-bit switching capability with a single output-enable control, distinguishing it from other multi-channel switches by its integrated biasing and protection features tailored for dynamic bus systems.

Replacement Considerations

SN74CBT6845CRGYR