Texas Instruments SN74CBT16811CDGVR

Overview

SN74CBT16811CDGVR from Texas Instruments is a 24-bit FET bus switch organized as two independent 12-bit bidirectional switches, featuring 3 Ω typical ON-state resistance, −2 V undershoot protection on A/B ports, B-port precharge via BIASV pin, 0.15 ns typical propagation delay (VCC = 5 V), and support for 0–5-V signaling across 0.8 V to 5 V logic families. It enables hot-plug–compliant PCI interface isolation and live-insertion noise suppression in backplane systems.

For engineers reviewing the SN74CBT16811CDGVR datasheet, SN74CBT16811CDGVR pinout, SN74CBT16811CDGVR application, or SN74CBT16811CDGVR equivalent, key selection criteria include its dual 12-bit enable-controlled switching architecture, Ioff partial-power-down capability, BIASV-biased high-impedance state, and TSSOP-56 package compatibility with dense PCB layouts requiring low signal distortion and rail-to-rail voltage translation.

Technical Context

The SN74CBT16811CDGVR implements two independent 12-bit FET-based analog switches controlled by separate 1OE and 2OE inputs; each switch connects A and B ports bidirectionally when enabled (OE low) and isolates them with B-port precharged to BIASV when disabled. Its internal undershoot-protection circuitry actively clamps A/B port voltages down to −2 V without latch-up.

It operates across VCC = 4 V to 5.5 V and supports mixed-voltage I/O (0–5 V) with TTL/CMOS-compatible control inputs. The device guarantees Ioff < 10 µA at VCC = 0 V, enabling safe partial-power-down operation while maintaining isolation between powered and unpowered system domains.

Key Specifications

Pinout & Package

TSSOP-56 package (DGV), 1.2 mm max height, 0.5 mm pitch, body size 13.9 × 7.9 mm, lead finish NiPdAu, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT16811CDGVR, SN74CBTD16210DGGR requires lower supply voltage and adds direction control but forfeits hot-plug precharge; SN74CBT16210DGVR matches voltage and bias functionality but merges the two 12-bit banks into one 24-bit block, simplifying control at the cost of granular isolation.

Availability

SN74CBT16811CDGVR is available at Aetrix Electronics and suitable for PCI hot-plug interfaces, memory interleaving circuits, backplane bus isolation, and low-distortion analog signal gating requiring stable component supply and long-term industrial availability.

Supply support for SN74CBT16811CDGVR 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, longevity, and industrial-grade performance.

The SN74CBT16811CDGVR belongs to TI's Widebus™ family of high-speed bus switches, designed specifically for zero-delay signal routing, hot-plug compliance, and mixed-voltage domain bridging in computing, telecom, and industrial backplane architectures.

FAQ

What is the maximum undershoot voltage the SN74CBT16811CDGVR can tolerate on its A and B ports?

The SN74CBT16811CDGVR provides active undershoot protection down to −2 V on both A and B ports, as verified in the absolute maximum ratings and functional test conditions. This clamping behavior is implemented via internal circuitry that senses undershoot events and forces the switch into a safe OFF state, preventing false logic transitions or damage to connected receivers. The −2 V limit applies across the full operating temperature range and is independent of VCC or BIASV settings. SN74CBT16811CDGVR maintains this protection without requiring external components.

How does the BIASV pin function in the SN74CBT16811CDGVR during power-down or high-impedance states?

When either 1OE or 2OE is high (switch OFF) or when VCC = 0 V, the SN74CBT16811CDGVR precharges all associated B-port pins to the externally supplied BIASV voltage through an internal ~10-kΩ equivalent resistor. This ensures the B-port remains at a known, non-floating voltage-critical for suppressing live-insertion noise and preventing receiver threshold violations. BIASV must be supplied within 0 V to VCC (or 0 V to 5.5 V if VCC is absent), and SN74CBT16811CDGVR guarantees B-port output voltage stays within V_BIASV ± 0.1 V under these conditions.

Can the SN74CBT16811CDGVR be used to interface 1.8-V and 3.3-V logic domains bidirectionally?

Yes, the SN74CBT16811CDGVR supports true bidirectional 0–5-V signaling on all data I/Os (A and B ports), making it fully compatible with 1.8-V and 3.3-V logic levels without level shifters. Its control inputs accept TTL- or CMOS-level signals, and its low ON-state resistance (3 Ω typical) ensures minimal voltage drop and timing skew across mixed-voltage paths. SN74CBT16811CDGVR has been validated for use in such applications per its recommended operating conditions and electrical characteristics tables.

What is the typical ON-state resistance (ron) of the SN74CBT16811CDGVR and how does it affect signal integrity?

The SN74CBT16811CDGVR exhibits a typical ON-state resistance of 3 Ω at VCC = 4.5 V and IO = 30 mA, with a maximum of 6 Ω across temperature and voltage extremes. This low ron minimizes voltage drop across the switch (e.g., <180 mV at 60 mA), preserves signal rise/fall times, and reduces RC-induced propagation delay-key for maintaining timing margins in high-speed buses. SN74CBT16811CDGVR's ron consistency across channels also ensures matched delay paths in parallel data lanes.

Does the SN74CBT16811CDGVR support partial-power-down operation, and how is it implemented?

Yes, the SN74CBT16811CDGVR supports partial-power-down via its Ioff feature: when VCC = 0 V, leakage current into any I/O pin is limited to ≤10 µA, preventing damaging backflow current from powered subsystems into the unpowered device. This is achieved through internal transistor cutoff design and is specified per JESD 78 Class II latch-up standards. SN74CBT16811CDGVR maintains high-impedance isolation between A and B ports under these conditions, enabling safe coexistence with active rails in hot-swap architectures.