Texas Instruments SN74CB3T3383DWR

Overview

SN74CB3T3383DWR from Texas Instruments is a 10-bit FET bus-exchange switch with bidirectional data flow, 5 Ω typical ON-state resistance, near-zero propagation delay (0.15 ns at 2.5 V), and mixed-mode voltage translation supporting 0–5 V I/O signaling across 2.3–3.6 V VCC. It enables dynamic bus swapping in memory interleaving and level-translating interfaces between 5-V TTL, 3.3-V LVTTL, and 2.5-V CMOS domains.

For engineers reviewing the SN74CB3T3383DWR datasheet, SN74CB3T3383DWR pinout, SN74CB3T3383DWR application, or SN74CB3T3383DWR equivalent, this device is selected for low-latency, high-isolation bus switching where VCC-tracking translation, Ioff partial-power-down protection, and 5-V-tolerant I/Os are required in portable and embedded systems.

Technical Context

The SN74CB3T3383DWR implements five independent 2-bit bidirectional FET switches controlled by BE (bus-exchange enable) and BX (exchange select). Each switch uses low-threshold MOSFETs with gate drive derived from VCC to achieve ron ≈ 5 Ω and Cio(OFF) = 8 pF, enabling sub-nanosecond signal pass-through without direction control logic.

Voltage translation is achieved via passive tracking: output high level approximates VCC when VIH ≥ VCC − 1 V, supporting seamless interfacing across 0.8 V to 5 V logic families. Ioff circuitry actively isolates I/O ports during power-down, preventing backdrive current exceeding 10 µA even with VCC = 0 V and VI/O = 5.5 V.

Key Specifications

Pinout & Package

SN74CB3T3383DWR is housed in a 24-pin SOIC (DW) package, 7.5 mm × 15.4 mm body, 1.27 mm pitch, with standard JEDEC MS-013AC footprint and moisture sensitivity level 1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT3383CDWR and SN74LVC1G3157DCKR, the SN74CB3T3383DWR uniquely combines Ioff-enabled power-down safety, VCC-tracking translation across 2.3–3.6 V, and integrated 5-bit bus-exchange logic - making it irreplaceable for mixed-voltage, hot-pluggable, or low-power-isolation architectures.

Availability

SN74CB3T3383DWR is available at Aetrix Electronics and suitable for memory interleaving, processor-peripheral bridging, and hot-swappable backplane applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for SN74CB3T3383DWR 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 expertise in high-speed interface and power management ICs.

The SN74CB3T3383DWR belongs to TI's CB3T family of advanced bus switches, designed specifically for low-latency, mixed-voltage digital interconnect in portable, industrial, and communications equipment.

FAQ

What is the maximum data rate supported by the SN74CB3T3383DWR?

The SN74CB3T3383DWR does not specify a fixed data rate limit but delivers 0.15 ns minimum propagation delay at 2.5 V VCC, enabling reliable operation with signal edges faster than 200 ps. Real-world bandwidth depends on PCB layout, load capacitance, and driver strength - typical use cases include DDR SDRAM address/data multiplexing and 100-MHz+ parallel buses. The SN74CB3T3383DWR's 8 pF off-capacitance and 5 Ω ron preserve signal fidelity under these conditions.

Can the SN74CB3T3383DWR translate between 1.8-V and 3.3-V logic levels?

Yes. The SN74CB3T3383DWR supports 0–5 V I/O signaling with VCC set to 2.3–3.6 V. When VCC = 3.3 V, a 1.8-V input produces an output ≈3.3 V (since VIH ≥ VCC − 1 V = 2.3 V is satisfied), and a 3.3-V input yields VOH ≈3.3 V. This makes the SN74CB3T3383DWR suitable for bidirectional 1.8-V ↔ 3.3-V translation without external components.

Does the SN74CB3T3383DWR require external pull-up resistors on BE or BX pins?

Yes - to ensure high-impedance state during power-up/power-down, BE must be tied to VCC through a pull-up resistor. TI specifies the minimum value based on the driving source's current-sinking capability; typical values range from 4.7 kΩ to 10 kΩ. BX may be driven directly by CMOS or TTL logic but must never float - unused BX pins should be held at VCC or GND per recommended operating conditions. This requirement applies to every instance of SN74CB3T3383DWR in a design.

Is the SN74CB3T3383DWR compatible with 5-V-only systems?

No - the SN74CB3T3383DWR requires VCC between 2.3 V and 3.6 V and cannot be powered from 5 V. However, its I/Os are 5-V tolerant: when VCC = 3.3 V, all A/B pins accept 0–5.5 V inputs and drive outputs up to ≈3.3 V. Thus, it interfaces safely with 5-V peripherals in a 3.3-V system, but cannot replace a true 5-V bus switch like the SN74CBT3383 series. This behavior is intrinsic to the SN74CB3T3383DWR's architecture.

How does the Ioff feature protect the SN74CB3T3383DWR during partial power-down?

The Ioff circuitry disables internal conduction paths when VCC = 0 V, limiting leakage current to ≤10 µA even with 5.5 V applied to any I/O pin. This prevents damaging reverse current from back-driving powered-down sections of a system - critical in hot-swap modules or multi-rail SoC designs. Unlike passive switches, the SN74CB3T3383DWR guarantees isolation without external circuitry, satisfying JESD78 latch-up immunity (>250 mA) and ensuring robustness during brown-out or staged power sequencing.