Texas Instruments SN74CB3T3384PWRG4

Overview

SN74CB3T3384PWRG4 from Texas Instruments is a 10-bit, 5-V/3.3-V bidirectional bus switch IC with 5-Ω on-state resistance, TTL-compatible control inputs, and integrated level-shifting diodes for 5-V-to-3.3-V signal translation. It operates across −40°C to 85°C and supports high-speed data routing in mixed-voltage memory and peripheral interfaces.

For engineers reviewing the SN74CB3T3384PWRG4 datasheet, SN74CB3T3384PWRG4 pinout, SN74CB3T3384PWRG4 application, or SN74CB3T3384PWRG4 equivalent, key selection criteria include its 0.25 ns propagation delay, dual independent 5-bit switch architecture with separate OE controls, and TSSOP-24 package compatibility with space-constrained industrial PCB layouts.

Technical Context

The SN74CB3T3384PWRG4 implements two independent 5-bit FET-based analog switches, each controlled by a dedicated output-enable (OE) input operating at TTL logic thresholds (V_IL = 0.8 V, V_IH = 2 V). Its internal structure integrates clamp diodes from I/O pins to V_CC, enabling reliable 5-V-to-3.3-V level shifting without external components.

When OE is low, the switch connects port A to port B with typical on-resistance of 5 Ω at V_CC = 4.5 V and I_I = 30 mA; when OE is high, both ports enter high-impedance state. Propagation delay is defined by the RC time constant of r_on and 50-pF load, yielding t_pd = 0.25 ns (typ).

Key Specifications

Pinout & Package

TSSOP-24 package (PW), 7.8 mm × 4.4 mm × 1.2 mm max height, lead pitch 0.65 mm, exposed pad not present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBTD3384PWR and TS3A27518EIPWR, the SN74CB3T3384PWRG4 uniquely combines 5-V-tolerant inputs, integrated level-shifting diodes, and dual independent OE control - making it the only option among the three that delivers true plug-in 5-V-to-3.3-V bus switching without external circuitry or voltage-domain restrictions.

Availability

SN74CB3T3384PWRG4 is available at Aetrix Electronics and suitable for industrial automation controllers, telecom line cards, and embedded test instrumentation requiring stable component supply and long-term obsolescence management.

Supply support for SN74CB3T3384PWRG4 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 electronic components.

The SN74CB3T3384PWRG4 belongs to TI's CB3T family of high-speed bus switches, designed specifically for voltage-level translation and signal isolation in mixed-supply digital systems where timing integrity and design simplicity are critical.

FAQ

What is the maximum continuous current rating per channel for the SN74CB3T3384PWRG4?

The SN74CB3T3384PWRG4 supports a continuous channel current of 128 mA per switch path. This rating applies under recommended operating conditions (V_CC = 4.5 V to 5.5 V, T_A = −40°C to 85°C) and ensures thermal stability without derating in typical PCB layouts with moderate copper pour. Exceeding this current may trigger thermal shutdown or degrade r_on performance over time.

Does the SN74CB3T3384PWRG4 support true bidirectional signal flow without direction control pins?

Yes, the SN74CB3T3384PWRG4 provides fully bidirectional analog switching - signals pass equally well from A-to-B or B-to-A when the corresponding OE is low. No direction pin is required because the FET-based switch architecture is inherently symmetric; the device functions as a passive resistive bridge, not a digital transceiver with defined TX/RX roles.

Can the SN74CB3T3384PWRG4 be used to translate 3.3-V signals up to 5-V logic levels?

No - the SN74CB3T3384PWRG4 integrates diodes from I/O pins to V_CC, enabling safe 5-V-to-3.3-V level shifting only. Driving 3.3-V signals into a 5-V system requires an active translator or open-drain buffer with pull-up to 5 V; this device does not provide voltage boosting or level-up conversion capability.

What is the thermal resistance (θ_JA) of the SN74CB3T3384PWRG4 in its TSSOP-24 package?

The SN74CB3T3384PWRG4 in the PW (TSSOP-24) package has a specified junction-to-ambient thermal resistance (θ_JA) of 88°C/W under JEDEC-standard PCB mounting conditions (2-layer board, 1-in² copper). This value assumes no additional thermal vias or heatsinking; actual performance improves with enhanced PCB copper area and thermal relief design.

Are the 1OE and 2OE pins internally pulled up or down on the SN74CB3T3384PWRG4?

Neither 1OE nor 2OE is internally biased - both require explicit connection to V_CC or GND to ensure defined logic states. Leaving either OE pin floating violates recommended operating conditions and may cause partial turn-on, increased ICC, or unpredictable switching behavior. TI's application report SCBA004 mandates tying unused control inputs to valid rails.