Texas Instruments SN74CBTD3384DBQR

Overview

SN74CBTD3384DBQR from Texas Instruments is a 10-bit high-speed TTL-compatible bus switch IC with dual 5-bit independent switching channels, 5-Ω on-state resistance, TTL-level control inputs, and integrated level-shifting capability (5-V input to 3.3-V output). It operates from 4.5 V to 5.5 V and supports industrial temperature range (−40°C to 85°C), commonly used in mixed-voltage data path isolation between microcontrollers and peripheral buses.

For engineers reviewing the SN74CBTD3384DBQR datasheet, SN74CBTD3384DBQR pinout, SN74CBTD3384DBQR application, or SN74CBTD3384DBQR equivalent, key selection criteria include on-resistance matching, propagation delay under 0.25 ns, dual OE-controlled channel isolation, and SSOP-24 package compatibility with legacy 5-V/3.3-V interface designs.

Technical Context

The SN74CBTD3384DBQR implements two independent 5-bit bidirectional analog switches controlled by separate OE pins (1OE and 2OE), enabling selective connection between Port A (A1–A5) and Port B (B1–B5) per channel. Each switch exhibits low 5-Ω typical on-state resistance and supports rail-to-rail signal pass-through without added propagation delay.

It integrates internal diodes to VCC for level shifting, allowing 5-V logic inputs to drive 3.3-V outputs while maintaining TTL-compatible input thresholds (VIH = 2 V min, VIL = 0.8 V max). The device draws only 1.5 mA ICC at 5.5 V and features fast enable/disable timing (ten ≤ 7 ns, tdis ≤ 5.3 ns) under 50-pF load conditions.

Key Specifications

Pinout & Package

SN74CBTD3384DBQR is housed in a 24-pin SSOP (Shrink Small-Outline Package), designated DBQ, with 0.65-mm lead pitch and JEDEC MO-153 compliance. The package measures 7.9 mm × 4.4 mm × 1.2 mm max height and features gull-wing leads for surface-mount assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBTD3384DBQR, SN74CBT3384DBQR trades integrated level shifting for lower static current, while SN74LVC1G3157DCKR offers voltage flexibility and smaller size at the cost of channel count and bus-oriented architecture.

Availability

SN74CBTD3384DBQR is available at Aetrix Electronics and suitable for industrial PLC backplanes, embedded memory expansion bridges, and PCIe slot adapter interfaces requiring stable component supply and long-term lifecycle support.

Supply support for SN74CBTD3384DBQR 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 heritage in high-reliability interface ICs.

The 'CBTD3384 product line was designed specifically for high-speed, low-latency bidirectional bus switching in mixed-voltage systems, targeting industrial control, communications infrastructure, and test equipment where signal integrity and timing predictability are critical.

FAQ

What is the maximum continuous current rating per channel for SN74CBTD3384DBQR?

The SN74CBTD3384DBQR supports a continuous channel current of 128 mA per switch path. This rating applies to any individual A–B connection (e.g., 1A1 to 1B1) under recommended operating conditions (VCC = 4.5 V to 5.5 V, TA = −40°C to 85°C). Exceeding this limit risks thermal degradation or parametric shift. Derating is advised above 70°C ambient.

Does SN74CBTD3384DBQR support true bidirectional signal flow without direction control pins?

Yes, SN74CBTD3384DBQR operates as a passive analog switch: signals pass bidirectionally between Port A and Port B when the corresponding OE is low, with no inherent directionality or internal drivers. Its 5-Ω on-resistance and rail-to-rail voltage handling (−0.5 V to 7 V) ensure symmetric performance regardless of signal source/sink orientation-ideal for data, address, and control lines in legacy parallel buses.

Can SN74CBTD3384DBQR be used to translate 3.3-V signals to 5-V levels?

No, SN74CBTD3384DBQR is optimized for 5-V-to-3.3-V level shifting only, via its integrated diode-to-VCC structure. Driving 3.3-V inputs into the device does not produce boosted 5-V outputs. For reverse translation, external circuitry (e.g., pull-up resistors to 5-V with appropriate current limiting) or a dedicated translator like SN74AVC4T245 is required. The SN74CBTD3384DBQR datasheet explicitly states its level-shifting function is unidirectional.

Is the SSOP-24 (DBQ) package of SN74CBTD3384DBQR RoHS compliant?

Yes, the SN74CBTD3384DBQR uses a RoHS-compliant lead finish (NIPDAU) and meets JEDEC MO-153 mechanical standards. Per TI's Package Option Addendum, the DBQ package carries "Yes" for RoHS status, with MSL Level-1 rating (unlimited floor life at ≤30°C/60% RH). No lead (Pb) is present in solderable terminations, and full compliance documentation is available through TI's quality portal.

How does the enable timing of SN74CBTD3384DBQR affect system-level bus arbitration?

The SN74CBTD3384DBQR provides fast, predictable enable/disable timing: ten ≤ 7 ns and tdis ≤ 5.3 ns (CL = 50 pF). This allows precise windowing of bus access-e.g., asserting 1OE just before a read cycle and deasserting it immediately after-minimizing contention windows in multi-master systems. The dual OE architecture further enables staggered channel activation, supporting time-multiplexed resource sharing without external glue logic.