Texas Instruments SN74CBT6800CDBQRE4

Overview

SN74CBT6800CDBQRE4 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 - deployed in PCI hot-plug interfaces and memory interleaving systems.

For engineers reviewing the SN74CBT6800CDBQRE4 datasheet, SN74CBT6800CDBQRE4 pinout, SN74CBT6800CDBQRE4 application, or SN74CBT6800CDBQRE4 equivalent, key selection criteria include live-insertion noise suppression via BIASV precharge, Ioff partial-power-down support, 0–5-V signal level compatibility, and TVSOP-24 package thermal performance (θJA = 86°C/W).

Technical Context

This device implements a TTL-compatible 10-bit FET switch architecture with independent A/B port undershoot sensing circuitry that forces OFF-state retention during −2 V transients. Its internal enable logic ensures bidirectional conduction only when ON is low, while B-port precharge to user-supplied BIASV minimizes live-insertion glitches.

The switch supports mixed-voltage signaling (0.8 V to 5 V) across data I/Os and accepts TTL/3.3 V/5 V CMOS control inputs. Ioff functionality guarantees isolation and prevents backflow current when VCC = 0 V, satisfying JESD 78 Class II latch-up requirements (>100 mA) and JESD 22 ESD robustness (2000-V HBM, 1000-V CDM).

Key Specifications

Pinout & Package

SN74CBT6800CDBQRE4 is housed in a 24-pin TVSOP (DGV) package, 4.4 mm × 6.6 mm × 1.2 mm, with 0.4-mm lead pitch and moisture sensitivity level 1 (260°C peak reflow). The package features exposed metal pad for thermal enhancement and is RoHS-compliant with NiPdAu lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT6800CDBQRE4, SN74CBTD6800CDBQR adds bus-hold but increases power and delay, while SN74LVC1G3157DCKR offers compact SPDT switching without parallel-bus or hot-plug capability - making SN74CBT6800CDBQRE4 uniquely suited for 10-bit live-insertion isolation.

Availability

SN74CBT6800CDBQRE4 is available at Aetrix Electronics and suitable for PCI hot-plug interfaces, memory interleaving systems, and low-distortion analog signal gating requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for SN74CBT6800CDBQRE4 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-reliability interface solutions.

SN74CBT6800CDBQRE4 belongs to TI's Widebus™ family of high-speed FET bus switches, engineered specifically for hot-plug-capable computing and communications infrastructure requiring robust signal integrity and power-domain isolation.

FAQ

What is the maximum undershoot voltage the SN74CBT6800CDBQRE4 can withstand on its A and B ports?

The SN74CBT6800CDBQRE4 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 by detecting sub-ground excursions and forcing the switch into a guaranteed OFF state to prevent false conduction or latch-up during hot-plug events.

Does the SN74CBT6800CDBQRE4 support partial-power-down operation, and how is it implemented?

Yes, the SN74CBT6800CDBQRE4 supports partial-power-down via its Ioff feature, which limits leakage current to 10 µA maximum when VCC = 0 V. This is achieved through internal circuitry that disables conduction paths and isolates the A/B ports, preventing damaging backflow current between powered and unpowered system domains - critical for modular or hot-swap architectures.

What is the role of the BIASV pin on the SN74CBT6800CDBQRE4, and what voltage range is supported?

The BIASV pin on the SN74CBT6800CDBQRE4 sets the precharge voltage applied to the B port when the switch is disabled (ON = high) or powered down. It accepts 0 V to VCC (4–5.5 V), enabling precise alignment with receiver input thresholds - for example, 2.4 V for 3.3-V LVTTL - to suppress live-insertion noise by avoiding the input transition region.

Can the SN74CBT6800CDBQRE4 interface between different logic voltage levels, such as 1.8-V and 5-V domains?

Yes, the SN74CBT6800CDBQRE4 supports 0–5-V signaling on all data I/Os (A1–A10 and B1–B10), making it compatible with 0.8-V, 1.2-V, 1.5-V, 1.8-V, 2.5-V, 3.3-V, and 5-V logic families. Its TTL-compatible control inputs accept 3.3-V or 5-V CMOS outputs, and VCC is independently supplied at 4–5.5 V - enabling seamless level-agnostic bidirectional data transfer.

What is the thermal performance of the SN74CBT6800CDBQRE4 in its TVSOP (DGV) package?

The SN74CBT6800CDBQRE4 in the TVSOP-24 (DGV) package has a junction-to-ambient thermal resistance (θJA) of 86°C/W, as specified in the TI package addendum. This value assumes standard JEDEC 2-layer board conditions and confirms suitability for moderate-power-density applications where ambient temperatures remain within −40°C to 85°C operating range.