Texas Instruments 74CB3T3383DBQRE4

Overview

74CB3T3383DBQRE4 from Texas Instruments is a 10-bit FET bus-exchange switch with bidirectional data flow, 5 Ω typical ON-state resistance, 2.3 V–3.6 V VCC operation, and voltage translation that tracks VCC for mixed-mode signaling. It enables level translation between 0–5 V I/O domains in memory interleaving and bus isolation applications.

For engineers reviewing the 74CB3T3383DBQRE4 datasheet, 74CB3T3383DBQRE4 pinout, 74CB3T3383DBQRE4 application, or 74CB3T3383DBQRE4 equivalent, key selection factors include its 0.15 ns propagation delay at 3.3 V, 8 pF OFF-state I/O capacitance, Ioff partial-power-down support, 5-V-tolerant I/Os, and SSOP-24 package compatibility with legacy 74CBT3383 designs.

Technical Context

The 74CB3T3383DBQRE4 implements a dual 5-bit bus-exchange architecture controlled by BE (bus-enable) and BX (exchange-select) inputs, enabling dynamic reconfiguration of A/B port mappings without direction control logic. Its FET-based switch topology delivers near-zero propagation delay and supports simultaneous 5-V/3.3-V/2.5-V signal domains on all I/Os.

Voltage translation is achieved via VCC-tracking output drive: VOH ≈ VCC when VIH ≥ VCC − 1 V, enabling seamless interfacing across TTL, LVTTL, and CMOS logic families. The device incorporates undershoot clamp diodes on all data/control inputs and meets JESD 17 latch-up (>250 mA) and JESD 22 ESD (2000-V HBM, 1000-V CDM) requirements.

Key Specifications

Pinout & Package

74CB3T3383DBQRE4 uses a 24-pin SSOP (Shrink Small-Outline Package) with 0.65 mm lead pitch, 8.2 mm × 3.9 mm body size, and JEDEC MO-153 compliance. Pin 1 is located at top-left corner (quadrant Q1), with GND (Pin 11) and VCC (Pin 12) adjacent for low-inductance decoupling.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT3383DBQR and 74LVC4052PW, the 74CB3T3383DBQRE4 uniquely combines VCC-tracking level translation, 5-V I/O tolerance, Ioff protection, and sub-0.25 ns propagation delay - making it the only option qualified for mixed-voltage memory interleaving and hot-pluggable bus architectures.

Availability

74CB3T3383DBQRE4 is available at Aetrix Electronics and suitable for memory subsystem design, processor bus isolation, multi-standard logic interfacing, and low-power portable I/O expansion requiring stable component supply and long-term industrial availability.

Supply support for 74CB3T3383DBQRE4 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 over 50 years of innovation in high-performance interface and signal-path components.

The 74CB3T3383DBQRE4 belongs to TI's CB3T advanced bus-switch family, designed specifically for high-speed, low-latency, mixed-voltage system interconnect in computing, communications, and industrial control applications.

FAQ

What is the maximum data rate supported by the 74CB3T3383DBQRE4?

The 74CB3T3383DBQRE4 does not specify a maximum data rate in its datasheet, as it is a passive FET switch without internal clocking. Its 0.15 ns propagation delay and 8 pF OFF-state capacitance enable reliable operation with NRZ signals up to 5+ Gbps in controlled-impedance PCB environments, provided layout minimizes stub length and crosstalk. Signal integrity depends on external termination and trace design rather than device bandwidth limits.

Does the 74CB3T3383DBQRE4 require external pull-up resistors on BE and BX inputs?

Yes - the 74CB3T3383DBQRE4 requires a pull-up resistor on the BE pin to VCC to ensure high-impedance state during power-up or when un-driven; TI recommends ≤10 kΩ for standard CMOS drivers. The BX pin may be tied directly to VCC or GND for static routing, but if driven dynamically, it also benefits from a pull-up/pull-down to prevent floating states that could cause undefined switching behavior in the 74CB3T3383DBQRE4.

Can the 74CB3T3383DBQRE4 translate 5-V inputs to 1.8-V outputs?

No - the 74CB3T3383DBQRE4 translates outputs to approximately VCC level, not to a lower fixed voltage. With VCC = 1.8 V, VOH ≈ 1.8 V only if VIH ≥ 0.8 V (VCC − 1 V), but the device's absolute maximum VCC rating is 3.6 V and minimum is 2.3 V. Therefore, 1.8-V operation is outside specification; the 74CB3T3383DBQRE4 supports 2.3–3.6 V VCC only, limiting output translation to 2.3–3.6 V ranges.

How does the Ioff feature protect the 74CB3T3383DBQRE4 during partial power-down?

The Ioff feature in the 74CB3T3383DBQRE4 disables internal conduction paths when VCC = 0 V, limiting reverse current through I/O pins to ≤10 µA even with 5.5 V applied externally. This prevents back-driving powered-down circuitry, avoids latch-up risk, and ensures safe hot-swap capability - critical when integrating the 74CB3T3383DBQRE4 into modular backplane or field-upgradeable systems.

Is the 74CB3T3383DBQRE4 pin-compatible with earlier SN74CBT3383 variants?

Yes - the 74CB3T3383DBQRE4 shares identical pinout, package footprint (SSOP-24 DBQ), and signal mapping with SN74CBT3383DBQR and SN74CB3T3383DBQR. However, it adds VCC-tracking translation and Ioff support not present in CBT versions, so direct replacement is functionally safe but requires verifying that downstream logic accepts VOH ≈ VCC instead of fixed VOH = VCC − 0.2 V in the older 74CB3T3383DBQRE4 design.