Texas Instruments SN74CB3Q32245GKER

Overview

SN74CB3Q32245GKER from Texas Instruments is a high-bandwidth 32-bit FET bus switch organized as four independent 8-bit bidirectional switches, featuring 5-Ω typical ON-state resistance (ron), rail-to-rail 0–5-V switching capability with 3.3-V VCC, and 4-pF typical OFF-state I/O capacitance. It enables low-distortion signal gating in PCI interfaces and memory interleaving systems.

For engineers reviewing the SN74CB3Q32245GKER datasheet, SN74CB3Q32245GKER pinout, SN74CB3Q32245GKER application, or SN74CB3Q32245GKER equivalent, key selection criteria include partial-power-down support via Ioff, 20-MHz maximum OE switching frequency, flat ron over voltage range, and LFBGA-64 (GKE) package compatibility with high-density routing.

Technical Context

The SN74CB3Q32245GKER implements charge-pump-enhanced FET switches to maintain low and flat ON-state resistance across 0–5-V I/O signaling levels, enabling rail-to-rail operation without level-shifting circuitry. Its four independent 8-bit sections each feature dedicated OE inputs (1OE–4OE) for granular bus isolation control.

Each switch supports bidirectional data flow with near-zero propagation delay (0.18 ns typical at 3.3 V), sub-8 ns enable/disable times, and 5-V-tolerant I/Os even when powered down-enabling hot-swap and partial-power-down system architectures compliant with JESD 78 Class II latch-up immunity.

Key Specifications

Pinout & Package

LFBGA-64 (GKE) package, 5 mm × 5 mm, 0.5-mm pitch, bottom-side solder balls, moisture sensitivity level 3. Pinout validated per SCES622 Figure 1 (top view).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CB3Q32245GKER, SN74CBTLV3245PWR offers lower cost but sacrifices 5-V tolerance and hot-swap robustness, while PI3CH485LE trades off isolation safety and transient protection for slightly smaller footprint - making SN74CB3Q32245GKER optimal for mixed-voltage, safety-critical, or high-fidelity signal routing.

Availability

SN74CB3Q32245GKER is available at Aetrix Electronics and suitable for PCI interface design, memory interleaving systems, differential signal routing, and bus isolation applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for SN74CB3Q32245GKER 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 logic solutions, with decades of innovation in high-speed interface and signal-integrity technologies.

The SN74CB3Q32245GKER belongs to TI's Widebus+™ family of high-bandwidth FET bus switches, engineered specifically for low-distortion, rail-to-rail signal gating in broadband communications, networking infrastructure, and data-intensive computing platforms.

FAQ

What is the maximum signal frequency supported by the SN74CB3Q32245GKER?

The SN74CB3Q32245GKER supports high-bandwidth data paths up to 500 MHz, as confirmed in the device's characterization report (SCDA008). This performance derives from its 5-Ω typical ON-state resistance and 4-pF OFF-state I/O capacitance, which jointly minimize RC delay and preserve signal edge rates. Actual usable frequency depends on PCB layout, load capacitance, and termination - but the SN74CB3Q32245GKER itself imposes no intrinsic bandwidth limit below 500 MHz.

Does the SN74CB3Q32245GKER support hot-swap or partial-power-down operation?

Yes, the SN74CB3Q32245GKER fully supports partial-power-down via its Ioff circuitry, limiting current backflow to 1 µA when VCC = 0. This allows safe insertion/removal while other system rails remain active. The device also features 5-V-tolerant I/Os regardless of VCC state, and undershoot clamp diodes protect against −1.8-V transients - all critical for robust hot-swap implementation in server backplanes and modular instrumentation.

Can the SN74CB3Q32245GKER operate with 2.5-V VCC while switching 0–3.3-V signals?

Yes, the SN74CB3Q32245GKER explicitly supports 0–3.3-V switching with 2.5-V VCC, as stated in the datasheet's "Rail-to-Rail Switching" section. Its integrated charge pump ensures the pass transistor remains fully enhanced across this combination, delivering flat 5-Ω ron and maintaining sub-0.3-ns propagation delay. This capability eliminates external level shifters in mixed-supply systems such as FPGA I/O banks interfacing with 3.3-V peripherals.

How many independent bus switch sections does the SN74CB3Q32245GKER provide?

The SN74CB3Q32245GKER provides four independent 8-bit bus switch sections, each controlled by its own active-low output-enable input (1OE through 4OE). These can be configured flexibly: as four separate 8-bit switches, two 16-bit switches (by tying adjacent OEs), or one unified 32-bit switch (by tying all four OEs together). This configurability enables precise bus segmentation in complex memory or I/O expansion architectures.

What package type and pin count does the SN74CB3Q32245GKER use?

The SN74CB3Q32245GKER uses the LFBGA-64 (GKE) package: a 5 mm × 5 mm, 0.5-mm pitch, 64-ball grid array with exposed thermal pad. It contains 32 bidirectional data pins (divided into four A/B port groups), four OE controls, eight ground balls, two VCC balls, and four NC positions. This compact, high-I/O-density package supports fine-pitch routing for space-constrained high-speed designs.