Texas Instruments SN74CBT3384DW

Overview

SN74CBT3384DW from Texas Instruments is a 10-bit TTL-compatible bus crossbar switch with dual 5-bit independent switching paths, 5 Ω typical on-resistance, sub-1 ns enable/disable timing, and operation over 0°C to 70°C. It connects A- and B-side ports bidirectionally under separate OE1/OE2 control for high-speed data routing in backplane and memory interface applications.

For engineers reviewing the SN74CBT3384DW datasheet, SN74CBT3384DW pinout, SN74CBT3384DW application, or SN74CBT3384DW equivalent, key selection criteria include its 5 Ω on-resistance, dual OE control logic, 0.25 ns propagation delay, 50 pF load drive capability, and DW-package thermal dissipation (1.6 W at 55°C).

Technical Context

The SN74CBT3384DW implements two independent 5-bit analog/digital bus switches with CMOS control inputs and bipolar-compatible output levels. Each switch path features low-capacitance (6 pF OFF-state), low-charge-injection design enabling glitch-free hot-swap and level-translating operation between 3.3 V and 5 V domains.

Its function table defines four states: both OEs low (full 10-bit pass-through), OE1 low/OE2 high (A1–A5 ↔ B1–B5 only), OE1 high/OE2 low (A6–A10 ↔ B6–B10 only), and both high (all ports high-Z). No internal latching or clocking - purely transparent analog switching.

Key Specifications

Pinout & Package

DW package: 24-pin plastic small-outline (SOIC) with 300-mil body width, 1.27 mm pitch, and standard JEDEC MS-013AC footprint. Pin 12 = GND, Pin 13 = VCC, Pin 1 = OE1, Pin 24 = OE2.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBTD3384DW and QS3384P, the SN74CBT3384DW offers optimal balance of low power (50 µA ICC), compact SOIC packaging, and proven 5 Ω Ron performance - making it ideal for space-constrained, thermally managed commercial designs requiring clean bus switching without hold functionality.

Availability

SN74CBT3384DW is available at Aetrix Electronics and suitable for memory interfacing, backplane routing, hot-swap module interfaces, and legacy bus expansion requiring stable component supply and long-term industrial availability.

Supply support for SN74CBT3384DW 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 founded in 1930, delivering analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.

The SN74CBT3384DW belongs to TI's CBT (Crosspoint Bus Transceiver) logic family, engineered specifically for low-latency, low-distortion analog switching in high-speed digital systems where signal integrity and timing predictability are critical.

FAQ

What is the maximum continuous current rating per channel for the SN74CBT3384DW?

The SN74CBT3384DW supports up to 128 mA continuous channel current per switch path, verified under absolute maximum ratings. This rating applies to any individual A/B pin pair (e.g., A1↔B1) when VCC = 5 V and ambient temperature ≤55°C. Exceeding this current may trigger thermal shutdown or degrade on-resistance stability over time. The SN74CBT3384DW datasheet specifies this limit in Section "Absolute Maximum Ratings".

Does the SN74CBT3384DW support mixed-voltage operation between 3.3 V and 5 V domains?

Yes, the SN74CBT3384DW supports bidirectional level translation without external components. Its TTL-compatible inputs accept 3.3 V logic highs, and its low on-resistance (5 Ω typical) allows clean pass-through of 3.3 V signals to 5 V loads. However, VCC must remain at 5 V; the SN74CBT3384DW does not operate from 3.3 V supply. This behavior is confirmed in the "Recommended Operating Conditions" and "Electrical Characteristics" tables.

Can the SN74CBT3384DW be used in hot-swap applications?

Yes, the SN74CBT3384DW is suitable for hot-swap due to its ±50 mA input clamp current rating and high-impedance OFF-state (6 pF Cio). When OE is high, the A/B ports present minimal capacitive load and resistive leakage, preventing disturbance to live buses. The SN74CBT3384DW also exhibits low charge injection (<1 pC), reducing glitch risk during insertion. These characteristics are documented in the "Absolute Maximum Ratings" and "Electrical Characteristics" sections.

What is the thermal performance of the SN74CBT3384DW in the DW package?

The SN74CBT3384DW in the DW (SOIC) package has a maximum power dissipation of 1.6 W at TA = 55°C in still air, per the "Absolute Maximum Ratings" table. Its thermal resistance θJA is 55°C/W, meaning junction temperature rises ~88°C above ambient at full 1.6 W dissipation. For reliable operation, keep power below 1 W in enclosed environments. The SN74CBT3384DW datasheet provides derating curves in the "Package Thermal Considerations" note.

How does the SN74CBT3384DW differ from the SN74CBTD3384DW?

The SN74CBT3384DW lacks bus-hold circuitry, resulting in lower ICC (50 µA vs. 200 µA typical) and simpler I/O behavior. The SN74CBTD3384DW adds weak pull-up/pull-down on all pins to prevent floating states - useful in unterminated buses but increasing static power. Both share identical Ron, timing, and pinout. The SN74CBT3384DW is preferred when deterministic high-Z states and minimal quiescent current are required.