Texas Instruments SN74CBT6800CDGVRE4

Overview

SN74CBT6800CDGVRE4 from Texas Instruments is a 10-bit bidirectional FET bus switch with near-zero propagation delay (0.15 ns typical at 5 V), 3 Ω typical ON-state resistance, and active undershoot protection up to −2 V on both A and B ports. It supports live insertion and hot-plug applications in PCI-compliant systems with bias voltage (BIASV) precharge for noise suppression.

For engineers reviewing the SN74CBT6800CDGVRE4 datasheet, SN74CBT6800CDGVRE4 pinout, SN74CBT6800CDGVRE4 application, or SN74CBT6800CDGVRE4 equivalent, key selection criteria include Ioff partial-power-down capability, 0–5-V signal level compatibility across 10 data lines, and TVSOP-24 package suitability for high-density PCB layouts.

Technical Context

This device implements a TTL-compatible 10-bit bus switch architecture with independent A/B port isolation and dynamic B-port precharge via external BIASV supply. Its internal FET structure enables bidirectional signal flow with minimal RC delay-propagation time derived from r_on (3 Ω) and load capacitance (50 pF).

The undershoot-protection circuitry actively monitors A/B port voltages and forces OFF-state retention during −2 V transients, while Ioff functionality prevents backflow current when VCC = 0 V. Control inputs accept TTL or 3.3/5-V CMOS logic levels, and data I/Os operate from 0 V to 5.5 V regardless of VCC state.

Key Specifications

Pinout & Package

SN74CBT6800CDGVRE4 uses a 24-pin TVSOP (DGV) package, 4.4 mm × 6.6 mm footprint, 1.2 mm max height, 0.4 mm pitch, JEDEC MO-153 compliant. Pin 1 index located at top-left corner (Q1 quadrant in tape).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bus switch applications.

Compared with SN74CBTD6800CDGVR, SN74CBT6800CDGVRE4 provides lower signal attenuation and tighter timing control due to absence of built-in termination; versus SN74CB3Q6800PWR, it delivers superior thermal dissipation and reduced off-state loading in the same pin count but different package outline.

Availability

SN74CBT6800CDGVRE4 is available at Aetrix Electronics and suitable for PCI hot-plug interfaces, memory interleaving subsystems, and legacy voltage bridging applications requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for SN74CBT6800CDGVRE4 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies, with decades of expertise in high-speed interface solutions and industrial-grade reliability.

SN74CBT6800CDGVRE4 belongs to TI's Widebus™ family of high-speed FET bus switches, engineered specifically for zero-delay signal gating, hot-plug robustness, and mixed-voltage system interoperability in computing and communications infrastructure.

FAQ

What is the maximum undershoot voltage the SN74CBT6800CDGVRE4 can withstand on its A and B ports?

The SN74CBT6800CDGVRE4 provides active undershoot protection up to −2 V on both A and B ports, as verified in the absolute maximum ratings and functional testing per SCDS138. This protection operates independently of VCC state and ensures the switch remains in the OFF state during transient negative excursions, preventing bus corruption during live insertion events.

Does the SN74CBT6800CDGVRE4 support partial-power-down mode, and how is it implemented?

Yes, the SN74CBT6800CDGVRE4 supports partial-power-down mode via its Ioff feature. When VCC = 0 V, Ioff limits current flow through the switch to ≤10 µA-even with valid signals present on A or B ports-preventing damaging back-current between powered and unpowered system domains. This behavior is confirmed in the electrical characteristics table and functional description of SCDS138.

What is the role of the BIASV pin on the SN74CBT6800CDGVRE4, and what voltage range is allowed?

The BIASV pin on the SN74CBT6800CDGVRE4 sets the precharge voltage for the B-port terminals (B1–B10) when the switch is disabled (ON = high) or powered down (VCC = 0 V). It accepts 0 V to VCC, allowing precise alignment with receiver input thresholds (e.g., 2.4 V for 3.3-V LVTTL). This minimizes live-insertion noise by holding B-port nodes outside the input transition region.

Can the SN74CBT6800CDGVRE4 interface between 1.8-V and 3.3-V logic domains without level-shifting circuitry?

Yes, the SN74CBT6800CDGVRE4 supports 0–5.5-V signaling on all A/B I/Os regardless of VCC (4–5.5 V), enabling direct bidirectional interfacing between 1.8-V, 2.5-V, 3.3-V, and 5-V logic domains. No external level shifters are required because the device acts as a passive, low-r_on conductive path-not an active translator-and maintains signal integrity via 5.5 pF C_io(OFF) and 3 Ω r_on.

What is the thermal resistance (θJA) of the SN74CBT6800CDGVRE4 in its TVSOP-24 (DGV) package?

The SN74CBT6800CDGVRE4 in the TVSOP-24 (DGV) package has a junction-to-ambient thermal resistance (θJA) of 86°C/W, as specified in the absolute maximum ratings section of SCDS138. This value assumes standard JEDEC test conditions (single-layer board, no copper pour) and informs thermal design for continuous 128 mA per channel operation within −40°C to 85°C ambient.