Texas Instruments SN74CBT3383CDBQR

Overview

SN74CBT3383CDBQR from Texas Instruments is a 10-bit FET bus-exchange switch optimized for high-speed TTL-compatible digital signal routing in 5-V systems. It provides bidirectional data flow with near-zero propagation delay (0.15 ns typical at VCC = 5 V), 3 Ω typical on-state resistance, −2-V undershoot protection on A/B ports, and supports mixed-voltage I/O signaling (0–5 V). It enables byte-swapping and low-distortion bus isolation in enterprise networking hardware.

For engineers reviewing the SN74CBT3383CDBQR datasheet, SN74CBT3383CDBQR pinout, SN74CBT3383CDBQR application, or SN74CBT3383CDBQR equivalent, key selection criteria include its 24-pin SSOP package, dual-mode bus exchange (controlled by BE and BX), Ioff partial-power-down support, and verified −2-V undershoot clamping-critical for robust operation in Ethernet switches and server backplanes.

Technical Context

The SN74CBT3383CDBQR implements a 5-bit bus-exchange architecture with two independent 5-bit paths (A1/A2 ↔ B1/B2), controlled by active-low Bus Enable (BE) and select (BX) inputs. When BE is low, the device routes signals bidirectionally; BX determines whether A1↔B1/A2↔B2 (BX low) or A1↔B2/A2↔B1 (BX high), enabling nibble-swap functionality for memory interleaving or PCI bus reconfiguration.

Its FET-based switch topology delivers low on-resistance (3–6 Ω at VCC = 4.5–5.5 V), minimal off-state capacitance (8 pF), and integrated undershoot-protection circuitry that actively holds the switch OFF during −2-V transients on A/B ports-eliminating false turn-on without external clamps.

Key Specifications

Pinout & Package

SN74CBT3383CDBQR is housed in a 24-pin SSOP (DBQ) package measuring 8.65 mm × 3.90 mm, with 0.65-mm lead pitch and RoHS-compliant NiPdAu finish (MSL Level-2-260°C-1 year).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT3383CDBQR, SN74CBTD3384CDBQR adds 3.3-V control compatibility at marginally higher cost, while 74FST3383DW offers pin-compatible SOIC packaging but sacrifices undershoot robustness and ON-resistance performance-making SN74CBT3383CDBQR optimal for new 5-V, high-reliability designs.

Availability

SN74CBT3383CDBQR is available at Aetrix Electronics and suitable for enterprise servers, Ethernet switches, and industrial PCs requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant production volumes.

Supply support for SN74CBT3383CDBQR 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 SN74CBT3383CDBQR belongs to TI's CBT (Crossbar Bus Technology) family, engineered specifically for ultra-low-latency, high-fidelity digital signal routing in mission-critical infrastructure equipment.

FAQ

What is the maximum operating temperature range for the SN74CBT3383CDBQR?

The SN74CBT3383CDBQR is rated for continuous operation from −40°C to +85°C ambient temperature, validated per JEDEC JESD22-A104 thermal cycling standards. This range supports deployment in enclosed server chassis and industrial enclosures without forced air cooling. The DBQ package's 61°C/W junction-to-ambient thermal resistance ensures safe silicon temperatures under typical 3-μA ICC loading and moderate PCB copper area.

Does the SN74CBT3383CDBQR support hot-swap applications?

Yes, the SN74CBT3383CDBQR supports hot-swap applications through three integrated features: Ioff circuitry blocks back-current when VCC is unpowered, −2-V undershoot protection prevents false turn-on during connector insertion transients, and the 3-Ω ron ensures minimal voltage drop during live insertion. These capabilities are validated per JEDEC JESD78 Class II latch-up testing and ANSI/ESDA/JEDEC JS-001 HBM ESD standards-making SN74CBT3383CDBQR suitable for PCIe add-in cards and modular telecom blades.

Can the SN74CBT3383CDBQR be used with 3.3-V logic controllers?

Yes, the SN74CBT3383CDBQR control inputs (BE and BX) accept 3.3-V CMOS logic levels directly: VIH(min) = 2.0 V and VIL(max) = 0.8 V at VCC = 4–5.5 V, fully covering 3.3-V output swing. However, its data I/O pins operate at 0–5-V signaling levels-so 3.3-V data sources/sinks must remain within that range. For full 3.3-V data domain compatibility, consider SN74CBTD3384CDBQR instead.

How does the BX pin affect signal routing in the SN74CBT3383CDBQR?

The BX pin configures the internal data path mapping of the SN74CBT3383CDBQR: when BX = low, A1↔B1 and A2↔B2 pairs are connected (straight-through mode); when BX = high, A1↔B2 and A2↔B1 pairs are connected (crossed/nibble-swap mode). This enables dynamic byte reordering without external logic-critical for memory interleaving and flexible bus topologies. Both modes maintain identical 0.15-ns tpd and 3-Ω ron.

Is a decoupling capacitor required for the SN74CBT3383CDBQR VCC pin?

Yes, a 0.1-μF ceramic decoupling capacitor is mandatory on the VCC pin of the SN74CBT3383CDBQR and must be placed within 3 mm of the pin with short, wide traces to minimize inductance. This suppresses high-frequency supply noise generated during fast switching transitions (sub-0.25-ns edges), preventing ground bounce and ensuring stable ron and tpd performance. TI recommends pairing it with a 1-μF bulk capacitor elsewhere on the 5-V rail for low-frequency stabilization.