Texas Instruments SN74CBTK6800DBQR

Overview

SN74CBTK6800DBQR from Texas Instruments is a 10-bit FET bus switch with precharged outputs and active-clamp undershoot protection, designed for high-speed TTL-compatible signal routing in hot-swap systems. It features 5-Ω on-state resistance, ±2 V undershoot clamping, and bias-voltage-controlled B-port precharge to minimize live-insertion noise in backplane and modular I/O applications.

For engineers reviewing the SN74CBTK6800DBQR datasheet, SN74CBTK6800DBQR pinout, SN74CBTK6800DBQR application, or SN74CBTK6800DBQR equivalent, this device supports critical design tasks including bidirectional signal isolation during hot-plug events, low-distortion data path switching in telecom line cards, and robust I/O protection in industrial control modules where undershoot transients exceed –2 V.

Technical Context

The SN74CBTK6800DBQR implements a single-enable 10-bit FET switch architecture with independent A/B port connections and integrated active-clamp circuitry on all I/Os. Its on-resistance (3–7 Ω typical) enables near-zero propagation delay (<0.35 ns at 4 V), while the BIASV-biased precharge path (via ~10-kΩ equivalent resistor) ensures stable output voltage during power-up or insertion.

Undershoot protection operates by sourcing current from VCC when input falls below –2 V, preventing pass-transistor turn-on and latch-up. The device meets JESD 78 Class II latch-up immunity (>100 mA) and exceeds JESD 22 ESD ratings: 2000-V HBM, 200-V MM, and 1000-V CDM.

Key Specifications

Pinout & Package

SN74CBTK6800DBQR uses a 24-pin SSOP (DBQ) package with 0.65 mm pitch, 7.9 mm × 4.5 mm body size, and 1.2 mm max height. Pin 1 is located in quadrant Q1 of the tape reel.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBTK6800DBQR, SN74CBT16210DLR offers higher channel count but lacks live-insertion features, while SN74CB3Q3245PWR provides smaller footprint and lower voltage operation but sacrifices undershoot resilience and precharge control-making SN74CBTK6800DBQR uniquely suited for 5-V hot-swap infrastructure.

Availability

SN74CBTK6800DBQR is available at Aetrix Electronics and suitable for modular telecom line cards, industrial PLC I/O modules, and server backplane interconnects requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for SN74CBTK6800DBQR 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 delivering analog, embedded processing, and connectivity solutions with emphasis on reliability, precision, and industrial-grade performance.

The SN74CBTK6800DBQR belongs to TI's CBTK bus switch family, engineered specifically for hot-pluggable system architectures where signal integrity, undershoot resilience, and controlled precharge during power transitions are critical.

FAQ

What is the function of the BIASV pin on the SN74CBTK6800DBQR?

The BIASV pin on the SN74CBTK6800DBQR sets the precharge voltage for the B port during disable or power-off states. When the ON input is high or VCC drops to 0 V, an internal ~10-kΩ path connects B1–B10 to BIASV, holding outputs at a stable, user-defined level (1.3 V to VCC) to prevent floating nodes and reduce live-insertion noise. This feature is integral to the SN74CBTK6800DBQR's hot-swap capability and distinguishes it from standard bus switches.

Does the SN74CBTK6800DBQR support true bidirectional signal flow?

Yes, the SN74CBTK6800DBQR supports fully bidirectional signal flow between A and B ports when enabled (ON = low). Its FET-based architecture has no inherent directionality-signals propagate with equal low on-resistance (3–7 Ω) and near-zero propagation delay (<0.35 ns) in either direction. This makes the SN74CBTK6800DBQR ideal for shared-data-bus applications such as backplane interconnects where data flows both toward and away from the switch.

How does the active-clamp undershoot-protection circuit work in the SN74CBTK6800DBQR?

The active-clamp undershoot-protection circuit in the SN74CBTK6800DBQR sources current from VCC to clamp I/O pins when voltage drops below –2 V. Unlike passive clamps, this circuit actively engages to prevent the internal pass transistor from turning on during negative transients, thereby avoiding latch-up and false logic states. This functionality is built into every I/O pin and is confirmed in the SN74CBTK6800DBQR's absolute maximum ratings and undershoot characteristics table.

What is the maximum continuous current rating per channel for the SN74CBTK6800DBQR?

The SN74CBTK6800DBQR has a continuous channel current rating of 128 mA per switch path, as specified in its Absolute Maximum Ratings table. This rating applies under normal operating conditions with VCC = 4–5.5 V and ambient temperature ≤85°C. Exceeding this current may degrade on-resistance stability or trigger thermal shutdown in sustained overload scenarios-designers should verify peak current in the SN74CBTK6800DBQR's actual application against this limit.

Is the SN74CBTK6800DBQR pin-compatible with other members of the SN74CBTK6800 family?

Yes, the SN74CBTK6800DBQR shares identical pinout and functional mapping with other variants in the SN74CBTK6800 family-including SN74CBTK6800DWR (SOIC), SN74CBTK6800PWR (TSSOP), and SN74CBTK6800DGVR (TVSOP)-all using the same 24-pin topology with ON, A1–A10, B1–B10, BIASV, VCC, and GND arranged identically. This allows direct PCB footprint reuse across package options while maintaining full electrical and timing compatibility in the SN74CBTK6800DBQR's operating range.