Texas Instruments 74CB3T16211DGGRE4

Overview

74CB3T16211DGGRE4 from Texas Instruments is a 24-bit FET bus switch IC with dual 12-bit configurable switching, 5-V tolerant I/Os, 2.3–3.6 V supply operation, and 5 Ω typical ON-state resistance-used for level translation and bus isolation in mixed-voltage PCI and embedded interface systems.

For engineers reviewing the 74CB3T16211DGGRE4 datasheet, 74CB3T16211DGGRE4 pinout, 74CB3T16211DGGRE4 application, or 74CB3T16211DGGRE4 equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated pin functions, and two confirmed alternative parts for voltage-translation bus switch applications requiring bidirectional low-latency signal routing.

Technical Context

The 74CB3T16211DGGRE4 implements two independent 12-bit FET-based analog switches controlled by separate OE inputs (1OE, 2OE), enabling either dual 12-bit or single 24-bit bus switching configurations. Its voltage-tracking output architecture ensures output levels follow VCC, supporting 5-V-to-3.3-V and 5-V/3.3-V-to-2.5-V level shifting.

Each switch channel features near-zero propagation delay (0.15 ns typ at 3.3 V), 5 pF OFF-state I/O capacitance, and Ioff protection that blocks backflow current during partial power-down-critical for hot-swap and mixed-rail system integrity. The device operates across –40°C to 85°C with full 5-V tolerance on all I/Os regardless of VCC state.

Key Specifications

Pinout & Package

TSSOP-56 (DGG) package: 12.0 mm × 6.1 mm body, 0.5 mm pitch, 1.2 mm max height, exposed metal pad not present, 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 SN74CBTLV3244RGYR and 74AVC16T245DGGR, the 74CB3T16211DGGRE4 uniquely combines 24-bit width, 5-V I/O tolerance, VCC-tracked level shifting, and Ioff in a single TSSOP-56 package-making it the only option for hot-pluggable, mixed-voltage, bidirectional bus isolation without external components.

Availability

74CB3T16211DGGRE4 is available at Aetrix Electronics and suitable for PCI Express slot isolation, legacy 5-V peripheral interfacing, multi-rail embedded memory bus sharing, USB 2.0 PHY routing, and industrial hot-swap applications requiring stable component supply and long-term lifecycle continuity.

Supply support for 74CB3T16211DGGRE4 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 high-reliability industrial and automotive-grade components.

The 74CB3T16211DGGRE4 belongs to TI's Widebus™ family of high-speed bus switches, designed specifically for low-latency, mixed-voltage signal routing in computing, communications, and industrial control systems where level translation and power sequencing robustness are critical.

FAQ

What is the maximum operating frequency supported by the 74CB3T16211DGGRE4?

The 74CB3T16211DGGRE4 does not specify a hard maximum clock frequency because it is an analog FET switch-not a clocked logic device. Its 0.15 ns typical propagation delay and 5 pF OFF-state capacitance enable reliable operation up to 500+ MHz in parallel bus applications when paired with appropriate trace impedance and termination. Actual usable bandwidth depends on PCB layout, load capacitance, and driver strength.

Does the 74CB3T16211DGGRE4 require external pull-up or pull-down resistors on its I/O pins?

No external pull-up or pull-down resistors are required on the 74CB3T16211DGGRE4 I/O pins for normal operation. The device includes internal undershoot clamp diodes and relies on the driven source to establish logic levels. However, OE pins must be pulled up to VCC via an external resistor (value determined by driver sink capability) to ensure high-impedance state at power-up.

Can the 74CB3T16211DGGRE4 be used for unidirectional signal routing only?

Yes-the 74CB3T16211DGGRE4 supports unidirectional use by connecting signals only to A-side or B-side pins and leaving the opposite side unused. Its bidirectional FET structure inherently works in either direction, and no configuration change is needed. This flexibility simplifies design reuse across both uni- and bi-directional interfaces like address/data multiplexing or control line isolation.

What is the thermal performance of the 74CB3T16211DGGRE4 in TSSOP-56 (DGG) package?

The 74CB3T16211DGGRE4 in TSSOP-56 (DGG) package has a junction-to-ambient thermal resistance (θJA) of 56°C/W, measured per JESD 51-7. At maximum ICC (70 μA) and typical ron (5 Ω), self-heating is negligible (<0.1°C). Under worst-case 24 mA per channel (288 mA total), power dissipation remains below 35 mW-well within safe limits for standard FR-4 PCBs without heatsinking.

How does the 74CB3T16211DGGRE4 handle power sequencing when VCC ramps after I/O signals are already present?

The 74CB3T16211DGGRE4 safely handles reverse power sequencing thanks to its 5-V tolerant I/Os and Ioff protection. When VCC = 0 V but I/Os sit at up to 5.5 V, leakage current is limited to 10 μA max-preventing damage or latch-up. This behavior is validated per JESD 78 and JESD 17, making the 74CB3T16211DGGRE4 suitable for hot-plug and modular backplane applications.