Texas Instruments SN74CBTD3384CDWRE4

Overview

SN74CBTD3384CDWRE4 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 level-shifting diode enabling 5-V-to-3.3-V translation. It supports memory interleaving and bus isolation in mixed-voltage digital systems.

For engineers reviewing the SN74CBTD3384CDWRE4 datasheet, SN74CBTD3384CDWRE4 pinout, SN74CBTD3384CDWRE4 application, or SN74CBTD3384CDWRE4 equivalent, key selection criteria include undershoot protection to −2 V, I_off-enabled partial-power-down operation, 0.15 ns propagation delay, and compatibility with 0.8–5-V signaling levels across A/B ports.

Technical Context

The SN74CBTD3384CDWRE4 implements two independent 5-bit FET-based analog/digital bus switches controlled by separate OE inputs (1OE, 2OE), each enabling bidirectional conduction between A and B ports when low. Its internal undershoot-protection circuitry actively monitors port voltage and forces OFF-state isolation during −2 V transients.

Level shifting is achieved via an integrated series diode between V_CC and the B-side I/Os, allowing 5-V inputs to drive 3.3-V logic thresholds without external components. The device operates within 4.5–5.5 V V_CC, supports I_off leakage ≤10 µA at V_CC = 0 V, and maintains <5 pF off-state I/O capacitance for minimal signal distortion.

Key Specifications

Pinout & Package

SN74CBTD3384CDWRE4 is housed in a 24-pin TSSOP (PW) package, 7.9 mm × 4.5 mm × 1.2 mm max height, with 0.65 mm lead pitch and pin 1 index area marked per JEDEC MO-153.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT3384CPWR and SN74LVC1G3157DCKR, SN74CBTD3384CDWRE4 uniquely combines 10-bit parallel switching, integrated 5-V-to-3.3-V translation, −2-V undershoot hardening, and industrial temperature qualification-enabling single-component solutions in mixed-voltage embedded bus architectures.

Availability

SN74CBTD3384CDWRE4 is available at Aetrix Electronics and suitable for memory interleaving, bus isolation, and low-distortion signal gating requiring stable component supply, long-term lifecycle assurance, and traceable sourcing for industrial control and communications equipment.

Supply support for SN74CBTD3384CDWRE4 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 decades of expertise in high-speed interface and power management ICs.

The SN74CBTD3384CDWRE4 belongs to TI's CBTD family of FET bus switches, designed specifically for low-latency, voltage-flexible digital interconnect in memory subsystems, industrial PLCs, and telecom infrastructure where signal integrity and robustness under transient stress are critical.

FAQ

What is the maximum undershoot voltage the SN74CBTD3384CDWRE4 can withstand on its A and B ports?

The SN74CBTD3384CDWRE4 provides active undershoot protection up to −2 V on both A and B ports. This is achieved through internal sensing circuitry that forces the switch into a guaranteed OFF state during such transients, preventing unintended conduction and potential damage. This specification is verified per the absolute maximum ratings and undershoot characteristics table in the official datasheet SCDS133A.

Does the SN74CBTD3384CDWRE4 support true bidirectional signal flow without direction control pins?

Yes, the SN74CBTD3384CDWRE4 supports fully bidirectional signal flow between A and B ports with no direction control required. When enabled (OE low), current flows equally well from A→B or B→A due to its symmetric FET switch topology. This eliminates the need for external direction logic and simplifies PCB routing in applications like memory data buses or shared I/O lines.

How does the integrated diode in the SN74CBTD3384CDWRE4 enable 5-V-to-3.3-V level shifting?

The SN74CBTD3384CDWRE4 integrates a diode in series between V_CC and the B-side I/Os. When a 5-V signal is applied to the A port, the diode drop (~0.7 V) and internal threshold design ensure the B port outputs ~3.3 V, compatible with 3.3-V logic. This occurs passively during forward conduction and is specified for reliable operation across the full 4.5–5.5 V V_CC range.

Can the SN74CBTD3384CDWRE4 be used in partial-power-down systems?

Yes, the SN74CBTD3384CDWRE4 features I_off circuitry that limits leakage current to ≤10 µA when V_CC = 0 V, preventing damaging back-current flow from live I/Os into a powered-down domain. This allows safe integration into systems with staggered power sequencing, such as multi-rail FPGAs or hot-pluggable modules, without external isolation components.

What is the typical ON-state resistance of the SN74CBTD3384CDWRE4, and how does it affect signal integrity?

The SN74CBTD3384CDWRE4 has a typical ON-state resistance (r_on) of 3 Ω at V_CC = 4.5 V and I_O = 30 mA. This low r_on minimizes voltage drop and power dissipation across the switch, preserving signal amplitude and reducing timing skew-critical for high-speed parallel buses and low-distortion analog gating applications.