Texas Instruments SN74CBT3383CDBR

Overview

SN74CBT3383CDBR from Texas Instruments is a 10-bit high-speed FET bus-exchange switch with bidirectional data flow, 3 Ω typical ON-state resistance (ron), −2 V undershoot protection on A/B ports, and 0.15 ns propagation delay at 5 V. It operates from 4 V to 5.5 V and supports mixed-voltage signaling (0.8 V to 5 V) in PCI interface and bus isolation applications.

For engineers reviewing the SN74CBT3383CDBR datasheet, SN74CBT3383CDBR pinout, SN74CBT3383CDBR application, or SN74CBT3383CDBR equivalent, key selection criteria include Ioff partial-power-down capability, 8 pF OFF-state I/O capacitance, BE/BX dual-control logic for port exchange, and SSOP-24 package compatibility with space-constrained board layouts.

Technical Context

The SN74CBT3383CDBR implements a 5-bit dual-path bus-exchange architecture controlled by BE (bus enable) and BX (bus exchange) inputs: when BE = L, A1↔B1 and A2↔B2; when BX = H, A1↔B2 and A2↔B1. Its FET-based switch core delivers near-zero propagation delay via low-impedance conduction paths.

Undershoot protection circuitry actively monitors A/B port voltages down to −2 V and forces switch disable during fault events. The device supports partial-power-down via Ioff (10 µA max at VCC = 0), preventing backflow current and enabling hot-insertion in powered systems.

Key Specifications

Pinout & Package

SN74CBT3383CDBR is housed in a 24-pin SSOP (Shrink Small Outline Package) with 0.64 mm lead pitch, 8.2 mm × 3.95 mm body size, and RoHS-compliant CU-NiPdAu finish. Thermal resistance θJA is 63°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBTD3383CDBR and PI3CH403QEX, the SN74CBT3383CDBR provides superior transient resilience (−2 V undershoot guard) and lower conduction loss (3 Ω vs. 5 Ω), making it optimal for noise-prone industrial bus isolation where signal fidelity and fault tolerance outweigh ultra-low ICC requirements.

Availability

SN74CBT3383CDBR is available at Aetrix Electronics and suitable for PCI interface design, memory interleaving architectures, and bus isolation systems requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for SN74CBT3383CDBR 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 IC design.

The SN74CBT3383CDBR belongs to TI's CBT (Crosspoint Bus Transceiver) family, engineered for high-speed digital interconnect applications demanding minimal propagation delay, robust ESD/undershoot immunity, and mixed-voltage signal routing.

FAQ

What is the maximum undershoot voltage the SN74CBT3383CDBR can tolerate on its A and B ports?

The SN74CBT3383CDBR tolerates up to −2 V undershoot on both A and B ports, enforced by active protection circuitry that forces the switch into the OFF state during such events. This specification is verified per test conditions in the SCDS175 datasheet with VCC = 5.5 V and switch OFF. The SN74CBT3383CDBR's clamping behavior prevents latch-up and maintains signal integrity in electrically noisy environments like PCI hot-plug scenarios.

Does the SN74CBT3383CDBR support partial-power-down mode, and how is it implemented?

Yes, the SN74CBT3383CDBR supports partial-power-down mode via its Ioff feature, which limits current to 10 µA maximum when VCC = 0 V while I/O voltages remain between 0 and 5.5 V. This prevents damaging backflow current during power sequencing or hot-swap operations. The SN74CBT3383CDBR achieves this through internal circuitry that disables the switch channel and isolates power domains, ensuring safe operation in systems with staggered supply activation.

What is the typical ON-state resistance (ron) of the SN74CBT3383CDBR, and how does it affect signal integrity?

The SN74CBT3383CDBR has a typical ON-state resistance of 3 Ω at VCC = 4.5 V and IO = 30 mA. This low ron minimizes voltage drop across the switch-less than 90 mV at 30 mA-preserving logic high/low thresholds and reducing IR-induced timing skew. In high-speed applications like PCI, this ensures signal edges remain sharp and noise margins are maintained, directly contributing to reliable data capture at multi-hundred-MHz rates. The SN74CBT3383CDBR's ron consistency across temperature and voltage further enhances system predictability.

How does the BE and BX control logic configure data routing in the SN74CBT3383CDBR?

The SN74CBT3383CDBR uses BE (pin 1, active-low) as the global enable and BX (pin 24) as the exchange selector. When BE = L, the device routes data: if BX = L, A1↔B1 and A2↔B2; if BX = H, A1↔B2 and A2↔B1. When BE = H, all ports enter high-impedance isolation. This dual-control scheme allows dynamic reconfiguration of 10-bit data paths without external logic. The SN74CBT3383CDBR's function table confirms these states, enabling flexible bus topology management in memory and interface subsystems.

What package type and thermal characteristics apply to the SN74CBT3383CDBR?

The SN74CBT3383CDBR is packaged in a 24-pin SSOP (DB) with 0.64 mm lead pitch, 8.2 mm × 3.95 mm body dimensions, and CU-NiPdAu lead finish. Its junction-to-ambient thermal resistance (θJA) is 63°C/W, measured per JESD 51-7. This package supports reflow soldering per JEDEC Level-2-260°C-1-year MSL rating and provides adequate thermal dissipation for continuous operation at 85°C ambient when dissipating ≤150 mW. The SN74CBT3383CDBR's compact SSOP footprint suits dense PCB layouts without compromising thermal performance.