Texas Instruments SN74CBTD3384CPW

Overview

SN74CBTD3384CPW from Texas Instruments is a 24-pin TSSOP 10-bit FET bus switch with dual 5-bit sections, 3 Ω typical ON-state resistance, −2 V undershoot protection on A/B ports, and integrated 5-V-to-3.3-V level shifting. It enables bidirectional signal gating in memory interleaving and bus isolation applications requiring low distortion and near-zero propagation delay (0.15 ns).

For engineers reviewing the SN74CBTD3384CPW datasheet, SN74CBTD3384CPW pinout, SN74CBTD3384CPW application, or SN74CBTD3384CPW equivalent, key selection criteria include VCC operating range (4.5–5.5 V), Ioff partial-power-down support, 5 pF OFF-state I/O capacitance, and compatibility with TTL/3.3-V/5-V control inputs.

Technical Context

The SN74CBTD3384CPW implements two independent 5-bit FET bus switches controlled by separate OE inputs (1OE, 2OE), supporting configuration as either two 5-bit or one 10-bit switch. Each switch uses low-threshold FETs with integrated clamp diodes to VCC for level shifting and undershoot protection.

Its architecture provides true bidirectional conduction with no direction pin, near-zero RC-delay propagation (tpd = 0.15 ns), and Ioff functionality that blocks backflow current during partial power-down. The device meets JESD 78 Class II latch-up (>100 mA) and JESD 22 ESD ratings (2000 V HBM, 1000 V CDM).

Key Specifications

Pinout & Package

TSSOP-24 package (PW), 7.9 mm × 4.5 mm body, 1.2 mm max height, 0.65 mm pitch, exposed metal pad not present, RoHS-compliant NIPDAU finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBTD3384CPW, SN74CBT3384CPW saves cost but adds design complexity for level shifting, while SN74LVC1G3157DBVR offers smaller footprint and wider VCC range but cannot replace 10-bit parallel switching functionality.

Availability

SN74CBTD3384CPW is available at Aetrix Electronics and suitable for memory subsystems, industrial bus interfaces, hot-pluggable module designs, and mixed-voltage signal routing requiring stable component supply and long-term manufacturability.

Supply support for SN74CBTD3384CPW 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 with over 50 years of innovation in high-reliability interface and signal-path ICs.

The SN74CBTD3384CPW belongs to TI's CBTD family of high-speed FET bus switches, engineered specifically for low-latency, low-distortion, mixed-voltage digital signal routing in memory, computing, and industrial control systems.

FAQ

What is the maximum undershoot voltage the SN74CBTD3384CPW can withstand on its A and B ports?

The SN74CBTD3384CPW provides active undershoot protection up to −2 V on both A and B ports, as verified in the absolute maximum ratings and undershoot characteristics table. This protection prevents unintended switch turn-on during negative transients, ensuring reliable OFF-state isolation even under harsh signal conditions. The SN74CBTD3384CPW achieves this via internal sensing circuitry that forces the FETs into cutoff when undershoot is detected.

Does the SN74CBTD3384CPW support true bidirectional signal flow without direction control pins?

Yes, the SN74CBTD3384CPW supports fully bidirectional data flow between A and B ports with no direction pin required. When 1OE or 2OE is low, the corresponding 5-bit switch conducts equally in both directions due to its symmetrical FET structure. This eliminates timing skew and control overhead in applications like memory address/data buses where signal direction changes dynamically. The SN74CBTD3384CPW maintains this behavior across its full 0–5.5 V VI/O range.

How does the integrated diode in series with VCC enable level shifting in the SN74CBTD3384CPW?

The SN74CBTD3384CPW integrates a diode between VCC and the internal switch array, creating a built-in 5-V-to-3.3-V level shifter. When a 5-V signal is applied to the A port, the diode drop (~1.7 V) reduces the effective gate drive seen by the FETs, allowing them to correctly interpret and pass the signal to a 3.3-V B-port load. This eliminates external translation components while maintaining rail-to-rail signal swing. The SN74CBTD3384CPW datasheet confirms this function operates across the full 4.5–5.5 V VCC range.

What is the purpose of the Ioff specification for the SN74CBTD3384CPW, and how does it benefit system design?

The Ioff specification (10 µA maximum at VCC = 0 V) ensures the SN74CBTD3384CPW blocks current flow between A and B ports when unpowered, preventing backfeeding into powered-down subsystems. This enables safe partial-power-down modes in multi-rail systems and supports hot-swap compliance. In practice, Ioff allows designers to isolate inactive modules without additional power-gating circuitry. The SN74CBTD3384CPW meets JESD 78 Class II latch-up immunity, reinforcing robustness during these conditions.

Can the SN74CBTD3384CPW be used with 1.8-V or 2.5-V logic families on its data I/O ports?

Yes, the SN74CBTD3384CPW explicitly supports 0–5.5 V signaling on its A and B ports, including 1.8-V and 2.5-V logic levels, as stated in the "Data I/Os Support 0 to 5-V Signaling Levels" feature list and confirmed in the recommended operating conditions table. Its low input/output capacitance (5 pF OFF, 12.5 pF ON) and rail-to-rail voltage tolerance ensure minimal distortion and full logic-level compatibility. The SN74CBTD3384CPW maintains specified ron and tpd performance across this entire range when VCC is within 4.5–5.5 V.