Texas Instruments SN74CB3T3383PWRG4

Overview

SN74CB3T3383PWRG4 from Texas Instruments is a 10-bit TTL-compatible bus-exchange switch operating at 4.5 V–5.5 V, featuring 5 Ω typical ON-state resistance, <1 ns propagation delay, and bidirectional signal routing with selectable nibble-swap mode via BX control. It enables byte-level bus reconfiguration in enterprise server backplanes.

For engineers reviewing the SN74CB3T3383PWRG4 datasheet, SN74CB3T3383PWRG4 pinout, SN74CB3T3383PWRG4 application, or SN74CB3T3383PWRG4 equivalent, key selection criteria include its 200 MHz bandwidth, 6 pF OFF-state capacitance, BE/BX dual-control logic, TSSOP-24 package compatibility, and support for 128 mA per channel switching without level translation.

Technical Context

The SN74CB3T3383PWRG4 implements a CMOS-based analog bus switch architecture with two independent control inputs: BE (active-low enable) governs overall conduction state, while BX selects between direct A↔B mapping (BX = L) and crossed 1A1↔1B2 / 1A2↔1B1 exchange (BX = H). All 10 channels operate simultaneously with near-zero propagation delay due to low r_ON and minimal parasitic capacitance.

It functions as either a 10-bit bidirectional switch or a 5-bit 2:1 multiplexer with exchange capability, supporting TTL- and 3.3-V/5-V CMOS-compatible logic thresholds (V_IL = 0.8 V, V_IH = 2.0 V) and delivering flat ON-resistance across the full 4.5–5.5 V supply range.

Key Specifications

Pinout & Package

TSSOP-24 package (7.80 mm × 4.40 mm body, 1.2 mm max height), lead finish NIPDAU, moisture sensitivity level MSL-1 (unlimited floor life).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CB3T3383PWRG4, SN74CBTD3384PW adds level shifting at the cost of increased rON and dual-supply complexity, while PI3CH480ELEX offers higher speed and lower resistance in a narrower 3.3-V, 8-bit form factor-neither replicates the exact 10-bit, 5-V, BX-enabled exchange functionality.

Availability

SN74CB3T3383PWRG4 is available at Aetrix Electronics and suitable for enterprise servers, Ethernet switches, and industrial PCs requiring stable component supply with guaranteed long-term sourcing.

Supply support for SN74CB3T3383PWRG4 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 decades of expertise in high-speed logic and interface solutions.

The SN74CBT3383 family was designed for high-fidelity, low-latency bus switching in telecom infrastructure, server backplanes, and industrial control systems where signal integrity and deterministic timing are critical.

FAQ

What is the maximum operating frequency supported by the SN74CB3T3383PWRG4?

The SN74CB3T3383PWRG4 supports up to 200 MHz operation, verified under CL = 50 pF load conditions with 4.5–5.5 V supply. Its 5 Ω typical ON-resistance and 6 pF OFF-state capacitance jointly enable this bandwidth while maintaining signal fidelity across PCB traces up to 15 cm in length.

Does the SN74CB3T3383PWRG4 require external level-shifting circuitry when interfacing with 3.3-V logic?

No, the SN74CB3T3383PWRG4 accepts 3.3-V CMOS logic levels directly: VIH = 2.0 V minimum and VIL = 0.8 V maximum ensure reliable recognition of 3.3-V high/low states. However, it does not translate 3.3-V inputs to 5-V outputs-it passes signals bi-directionally at the applied VCC voltage (4.5–5.5 V).

How does the BX pin affect signal routing in the SN74CB3T3383PWRG4?

When BX = H, the SN74CB3T3383PWRG4 swaps nibble pairs: 1A1 connects to 1B2, 1A2 to 1B1, 2A1 to 2B2, etc., enabling byte-level bus exchange. When BX = L, it operates as a standard 10-bit switch with 1A1↔1B1, 1A2↔1B2, etc. This mode is selected independently of BE activation.

What is the thermal performance of the SN74CB3T3383PWRG4 in its TSSOP-24 package?

In the TSSOP-24 package, the SN74CB3T3383PWRG4 has RθJA = 88.0 °C/W (junction-to-ambient) and RθJC(top) = 26.5 °C/W. At 128 mA per channel and 5 V supply, total power dissipation remains below 100 mW, keeping junction temperature rise under 9 °C above ambient in still air-no heatsink required.

Can the SN74CB3T3383PWRG4 be used in fail-safe configurations where signal integrity must be preserved during power loss?

Yes-the SN74CB3T3383PWRG4 features inherent fail-safe behavior: when VCC drops below ~2 V or is unpowered, all switches automatically enter high-impedance state (rOFF > 1 GΩ), preventing back-driving or leakage between A/B ports. This protects downstream devices during brown-out or hot-swap events.