Texas Instruments SN74CBTD3384CPWR

Overview

SN74CBTD3384CPWR from Texas Instruments is a 10-bit TTL-compatible FET bus switch with dual 5-bit sections, 3 Ω typical ON-state resistance, bidirectional signal flow, and integrated 5-V-to-3.3-V level shifting. It supports memory interleaving and bus isolation in mixed-voltage systems operating from 4.5 V to 5.5 V VCC.

For engineers reviewing the SN74CBTD3384CPWR datasheet, SN74CBTD3384CPWR pinout, SN74CBTD3384CPWR application, or SN74CBTD3384CPWR equivalent, key selection criteria include undershoot protection to −2 V, Ioff partial-power-down support, 0.15 ns propagation delay, 5 pF OFF-state I/O capacitance, and TSSOP-24 package compatibility with 0.65 mm pitch layouts.

Technical Context

The SN74CBTD3384CPWR implements two independent 5-bit FET bus switches controlled by separate OE inputs (1OE, 2OE), enabling flexible partitioning as either two 5-bit or one 10-bit switch. Each switch features active undershoot-protection circuitry on both A and B ports, clamping to −2 V while maintaining high-impedance isolation.

Its integrated series diode between VCC and the internal level-shifter enables robust 5-V input to 3.3-V output translation without external components. The device operates across 0–5.5 V data I/O signaling levels (including 0.8 V, 1.2 V, 1.5 V, 1.8 V, 2.5 V, 3.3 V, and 5 V), with TTL- and CMOS-compatible control inputs and Ioff functionality for safe partial-power-down operation.

Key Specifications

Pinout & Package

TSSOP-24 package (PW), 7.9 mm × 4.5 mm body, 0.65 mm lead pitch, 1.2 mm max height, RoHS-compliant NiPdAu finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBTD3384CPWR, SN74CBT3384CPWR offers lower ron but requires external level-shifting circuitry, while SN74LVC1G3157DBVR provides space savings for single-signal paths but cannot replicate 10-bit parallel bus control or −2 V undershoot immunity.

Availability

SN74CBTD3384CPWR is available at Aetrix Electronics and suitable for memory interleaving, bus isolation, and mixed-voltage logic interface applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant TSSOP packaging.

Supply support for SN74CBTD3384CPWR 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 for industrial, automotive, and communications markets.

The SN74CBTD3384CPWR belongs to TI's CBTD family of high-speed bus switches, designed specifically for low-distortion, level-shifting signal gating in multi-voltage digital systems with stringent timing and reliability requirements.

FAQ

What is the maximum undershoot voltage the SN74CBTD3384CPWR can withstand on its A and B ports?

The SN74CBTD3384CPWR provides active undershoot protection up to −2 V on both A and B ports, as verified in the absolute maximum ratings and undershoot characteristics section of the datasheet. This protection ensures the switch remains reliably OFF during negative transients, preventing unintended conduction or latch-up. The SN74CBTD3384CPWR achieves this via dedicated sensing circuitry that overrides normal switching behavior when undershoot is detected.

Does the SN74CBTD3384CPWR require external components to perform 5-V-to-3.3-V level shifting?

No, the SN74CBTD3384CPWR integrates a diode in series with VCC that enables native 5-V input to 3.3-V output level shifting without external resistors or translators. This feature is intrinsic to the SN74CBTD3384CPWR's internal architecture and functions automatically when VCC = 5 V and driven by 5-V signals on the A side. The SN74CBTD3384CPWR maintains bidirectional operation while providing this translation.

What is the recommended power-up sequence for the SN74CBTD3384CPWR to ensure high-impedance state at startup?

To guarantee high-impedance during power-up, OE pins (1OE and 2OE) must be held high until VCC stabilizes. TI recommends tying each OE to VCC through a pullup resistor; minimum value depends on driver sink strength but typically ≥10 kΩ. This prevents momentary bus contention before system initialization completes. The SN74CBTD3384CPWR's design relies on this external bias to enforce safe default state - no internal pullups are provided.

Can the SN74CBTD3384CPWR be used for analog signal switching, such as sensor outputs or audio paths?

Yes, the SN74CBTD3384CPWR supports analog signal switching due to its low 3 Ω ON-resistance, 5 pF OFF-capacitance, and rail-to-rail voltage handling (0–5.5 V). It has been characterized for low-distortion performance up to 100 MHz and is commonly deployed for DC-coupled sensor gating and low-frequency analog multiplexing. However, the SN74CBTD3384CPWR lacks guaranteed THD or bandwidth specs beyond digital timing parameters, so validation in the target analog application is advised.

What is the thermal resistance (θJA) of the SN74CBTD3384CPWR in its TSSOP-24 package?

The SN74CBTD3384CPWR in the PW (TSSOP-24) package has a junction-to-ambient thermal resistance (θJA) of 88°C/W, as specified in the Absolute Maximum Ratings table. This value assumes standard JEDEC high-k test board conditions (2S2P) and is critical for calculating maximum allowable power dissipation at given ambient temperatures. The SN74CBTD3384CPWR's low ron and fast switching minimize self-heating, making thermal derating rarely necessary below 50 mA per switch.