Texas Instruments SN74CB3T16212DGGR

Overview

SN74CB3T16212DGGR from Texas Instruments is a 24-bit FET bus-exchange switch with 5-V-tolerant level shifting, operating from 2.3 V to 3.6 V VCC. It supports bidirectional data flow between 12 A/B port pairs, delivers typ. 5 Ω ON-state resistance, 9 pF OFF-state I/O capacitance, and sub-0.25 ns propagation delay. Used in mixed-voltage memory interleaving and PCI interface isolation.

For engineers reviewing the SN74CB3T16212DGGR datasheet, SN74CB3T16212DGGR pinout, SN74CB3T16212DGGR application, or SN74CB3T16212DGGR equivalent, key selection criteria include 5-V-tolerant I/O operation with partial-power-down (Ioff), voltage translation tracking VCC, and TSSOP-56 package compatibility for high-density PCB layouts.

Technical Context

The SN74CB3T16212DGGR implements a TTL-compatible FET-based bus-exchange architecture with three select inputs (S0–S2) enabling eight configurable data path modes-including A↔B port exchange, A→B, B→A, or full disconnect. Each of its 24 bidirectional channels operates independently with near-zero propagation delay and no internal logic buffering.

Its level-shifting capability is defined by VCC-tracking output voltage: when VCC = 2.5 V, it translates 5-V/3.3-V inputs down to 2.5-V outputs; at VCC = 3.3 V, it shifts 5-V inputs to 3.3-V outputs. All I/Os remain 5-V tolerant whether powered or unpowered, and Ioff prevents backflow during partial power-down.

Key Specifications

Pinout & Package

TSSOP-56 (DGG) package: 13.9 mm × 6.0 mm × 1.2 mm body, 0.5 mm pitch, lead-free NiPdAu finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CB3T16212DGGR, SN74CBTLV3126PWR offers lower channel count and no exchange capability, while SN74AVC16T245DGGR provides dual-supply flexibility but sacrifices 5-V tolerance and Ioff safety-making SN74CB3T16212DGGR uniquely suited for mixed-voltage, hot-pluggable bus architectures.

Availability

SN74CB3T16212DGGR is available at Aetrix Electronics and suitable for PCI interface isolation, memory interleaving control, and USB 2.0 PHY interfacing requiring stable component supply across industrial temperature ranges (–40°C to +85°C).

Supply support for SN74CB3T16212DGGR 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 over 90 years of innovation in industrial, automotive, and communications markets.

The SN74CB3T16212DGGR belongs to TI's Widebus™ family of high-speed bus switches, engineered specifically for low-latency, mixed-voltage signal routing in computing, networking, and programmable logic systems.

FAQ

What is the maximum data rate supported by the SN74CB3T16212DGGR?

The SN74CB3T16212DGGR supports data rates exceeding 1 Gbps due to its 0.15–0.25 ns typical propagation delay and 5 Ω ON-state resistance. Real-world performance depends on PCB layout, trace length, and load capacitance-but the device is routinely deployed in DDR2-800 memory interfaces and full-speed USB 2.0 applications where timing margins are tight. SN74CB3T16212DGGR maintains signal fidelity without added jitter or skew across all 24 channels.

Does the SN74CB3T16212DGGR require external pull-up or pull-down resistors on its select inputs?

Yes-the SN74CB3T16212DGGR select inputs (S0, S1, S2) must be actively driven to valid logic levels; floating inputs may cause undefined switching states. TI recommends tying unused or default-select inputs to GND via pulldown resistors (value determined by driver strength) to ensure high-impedance isolation during power-up or reset. SN74CB3T16212DGGR does not include internal weak pull-ups or pull-downs on control pins.

Can the SN74CB3T16212DGGR translate 1.8-V signals to 3.3-V outputs?

No-the SN74CB3T16212DGGR performs downward level translation only: outputs track VCC, so a 1.8-V input yields a 1.8-V output when VCC = 1.8 V (outside spec), or a 2.5-V/3.3-V output only if the input exceeds VCC − 1 V. Its design supports 5-V→3.3-V and 5-V/3.3-V→2.5-V translation-not upward shifting. SN74CB3T16212DGGR cannot generate higher voltages than its VCC rail.

Is the SN74CB3T16212DGGR RoHS compliant and lead-free?

Yes-SN74CB3T16212DGGR is RoHS compliant with lead-free NiPdAu terminal finish, per TI's packaging documentation. It carries MSL Level-1 rating (unlimited floor life at ≤30°C/60% RH) and is qualified for reflow up to 260°C peak. The part marking "CB3T16212" appears on the top surface, and full compliance data is available in TI's Package Option Addendum dated November 2025.

How does the Ioff feature protect the SN74CB3T16212DGGR during partial power-down?

The Ioff feature disables internal FET conduction paths when VCC = 0 V, limiting reverse current to ≤10 µA-even with 5.5-V signals applied to I/O pins. This prevents backfeeding into a powered-down subsystem, avoids unintended logic state corruption, and eliminates risk of thermal overstress. SN74CB3T16212DGGR maintains this protection across the full –40°C to +85°C range, making it ideal for modular systems with staggered power sequencing.