Texas Instruments SN74CB3Q16211DGGR

Overview

SN74CB3Q16211DGGR from Texas Instruments is a 24-bit, 56-pin TSSOP low-voltage FET bus switch supporting rail-to-rail 0–5 V signaling at 2.5 V/3.3 V supply, with 5 Ω typical ON-state resistance, 500 MHz bandwidth, and bidirectional zero-delay switching for high-speed digital interconnects in memory and interface subsystems.

For engineers reviewing the SN74CB3Q16211DGGR datasheet, SN74CB3Q16211DGGR pinout, SN74CB3Q16211DGGR application, or SN74CB3Q16211DGGR equivalent, key selection criteria include its Ioff-enabled partial-power-down capability, 4 pF OFF-state I/O capacitance, 20 MHz maximum OE switching frequency, and compatibility with 0.8–5 V logic families across PCIe, DDR, and legacy parallel bus isolation use cases.

Technical Context

The SN74CB3Q16211DGGR implements two independent 12-bit FET bus switches with separate 1OE and 2OE controls, enabling flexible configuration as either dual 12-bit or single 24-bit paths. Its charge-pump gate drive ensures flat ron over voltage and temperature, maintaining signal integrity in high-bandwidth applications.

Each switch supports 5-V tolerant I/Os regardless of VCC state (2.3–3.6 V), features undershoot clamp diodes on all data and control pins, and guarantees latch-up immunity >100 mA per JESD78 Class II - critical for hot-swap and mixed-voltage system interoperability.

Key Specifications

Pinout & Package

TSSOP-56 (DGG) package: 14.00 mm × 6.10 mm body, 1.2 mm max height, 0.5 mm pitch, RoHS-compliant NiPdAu lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CB3Q16211DGGR, SN74CBT16211DGGR trades off power-down safety and voltage flexibility for lower unit cost, while PI3CH480ELEX offers tighter OFF-capacitance at the expense of 5-V tolerance and partial-power-down capability - making SN74CB3Q16211DGGR the optimal choice for mixed-voltage, hot-pluggable, or high-fidelity signal gating.

Availability

SN74CB3Q16211DGGR is available at Aetrix Electronics and suitable for PCIe interposers, DDR3 memory isolation, AV receiver signal routing, and DLP projector video bus gating requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for SN74CB3Q16211DGGR 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 signal integrity engineering.

The SN74CB3Q16211DGGR belongs to TI's Widebus® family of high-bandwidth FET bus switches, designed specifically for low-distortion, rail-to-rail signal gating in memory, PCIe, and multimedia subsystems where timing precision and voltage interoperability are critical.

FAQ

What is the maximum operating frequency supported by the SN74CB3Q16211DGGR?

The SN74CB3Q16211DGGR supports up to 500 MHz bandwidth for high-speed data paths, verified under loaded conditions with 30 pF test capacitance. Its 0.15–0.25 ns propagation delay and 5 Ω typical ON-state resistance enable reliable operation in PCIe Gen1 (2.5 Gbps) and DDR3-800 (400 MHz) applications without signal degradation.

Does the SN74CB3Q16211DGGR support partial-power-down mode?

Yes, the SN74CB3Q16211DGGR supports partial-power-down via its Ioff circuitry, limiting leakage to 1 µA when VCC = 0 V and VI/O = 0–5.5 V. This feature prevents damaging back-current flow between powered and unpowered sections of a system, making SN74CB3Q16211DGGR suitable for hot-plug and multi-rail architectures.

Can the SN74CB3Q16211DGGR interface 5-V signals while operating from a 2.5-V supply?

Yes, the SN74CB3Q16211DGGR supports 5-V tolerant I/Os across its full 0–5.5 V VI/O range, regardless of whether VCC is 2.5 V or 3.3 V. This allows direct interfacing with legacy 5-V peripherals without external level shifters - a confirmed capability documented in Section 7.1 Absolute Maximum Ratings and Section 5 Description.

What is the purpose of the charge pump in the SN74CB3Q16211DGGR?

The integrated charge pump elevates the gate voltage of the internal FET pass transistors to maintain low and flat ON-state resistance (ron ≈ 5 Ω) across the entire 2.3–3.6 V VCC range and 0–5 V signal swing. This architecture ensures consistent signal integrity and minimal propagation delay - a defining feature distinguishing SN74CB3Q16211DGGR from non-charge-pump alternatives like SN74CBT16211DGGR.

How many independent switch banks does the SN74CB3Q16211DGGR contain?

The SN74CB3Q16211DGGR contains two independent 12-bit bus switch banks, each controlled by its own active-low output-enable pin (1OE and 2OE). These can be used separately for dual-channel isolation or tied together to operate as a single 24-bit switch - a configuration explicitly defined in the Function Table (Table 5-1) and Pin Configuration section of the official datasheet.