Texas Instruments SN74LVT543DWR

Overview

SN74LVT543DWR from Texas Instruments is a 3.3-V ABT octal registered transceiver with 3-state outputs, featuring dual-directional latched data flow (A↔B), bus-hold inputs eliminating external pullups, and mixed-mode 5-V-tolerant I/O on a 3.3-V VCC supply. It operates from 2.7 V to 3.6 V and supports industrial temperature range (–40°C to 85°C) in a 24-pin SOIC (DW) package.

For engineers reviewing the SN74LVT543DWR datasheet, SN74LVT543DWR pinout, SN74LVT543DWR application, or SN74LVT543DWR equivalent, key selection criteria include bidirectional latch control (LEAB/LEBA, OEAB/OEBA), 3.3-V core with 5-V input tolerance, bus-hold functionality, output drive strength (IOL = 64 mA), and SOIC-DW package compatibility for space-constrained board layouts.

Technical Context

The SN74LVT543DWR implements two independent octal D-type latch registers-one for A-to-B and one for B-to-A data paths-each with dedicated latch-enable (LEAB/LEBA) and output-enable (OEAB/OEBA) controls. Its Advanced BiCMOS Technology (ABT) enables low static power dissipation while maintaining TTL-compatible switching performance at 3.3 V.

It supports live insertion and mixed-voltage system interfacing: inputs tolerate up to 5.5 V regardless of VCC, and outputs drive 5-V logic levels when VCC = 3.3 V. Bus-hold circuitry actively maintains valid logic states on unused A/B data inputs without external components.

Key Specifications

Pinout & Package

SN74LVT543DWR is housed in a 24-pin plastic small-outline integrated circuit (SOIC) package designated DW, with standard 0.300-inch body width and 1.27-mm lead pitch. The package is RoHS-compliant, green (Pb-free, no Sb/Br), and rated MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal registered transceiver applications.

Compared with SN74LVT543DWR, both alternatives lack integrated latches and bus-hold, require external timing control or pullups, and do not support 5-V inputs on 3.3-V VCC - making SN74LVT543DWR uniquely suited for legacy-system integration with minimal board-level changes.

Availability

SN74LVT543DWR is available at Aetrix Electronics and suitable for industrial PLC backplanes, legacy microcontroller bus bridges, modular test equipment backplanes, and automated test fixture data hubs requiring stable component supply and long-term design continuity.

Supply support for SN74LVT543DWR 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.

The SN74LVT543DWR belongs to TI's ABT (Advanced BiCMOS Technology) logic family, engineered for high-speed, low-power 3.3-V operation with robust mixed-voltage interoperability in industrial and instrumentation systems.

FAQ

What is the maximum operating voltage for SN74LVT543DWR inputs?

The SN74LVT543DWR supports input voltages up to 5.5 V regardless of VCC level, enabling direct connection to 5-V logic families without external level-shifting circuitry. This 5-V tolerance applies to all A and B data pins, as well as control inputs (LEAB, LEBA, OEAB, OEBA, CEAB, CEBA), and is specified across the full industrial temperature range (–40°C to 85°C). Absolute maximum rating is 7 V, but functional operation is guaranteed only to 5.5 V per recommended conditions.

Does SN74LVT543DWR require external pullup resistors on its data inputs?

No, SN74LVT543DWR does not require external pullup resistors on A1–A8 or B1–B8 inputs because it integrates active bus-hold circuitry. Each data input maintains a valid logic state (VIH ≥ 2.0 V or VIL ≤ 0.8 V) when floating, drawing ±75 µA hold current at VCC = 3 V. This eliminates board space, BOM cost, and layout complexity associated with discrete 10-kΩ pullups, and improves noise immunity in unterminated bus environments.

What is the function of the CEAB and CEBA pins on SN74LVT543DWR?

The CEAB (Chip Enable A-to-B) and CEBA (Chip Enable B-to-A) pins on SN74LVT543DWR act as master enable controls for each data path: CEAB must be low to allow A→B data latching or B-output driving, and CEBA must be low for B→A operation. When either CE pin is high, its corresponding path is disabled - the latches retain stored data, and outputs enter high-impedance state regardless of LE or OE status. This provides hierarchical control beyond OE, supporting power-aware or fault-isolation schemes in complex systems.

Can SN74LVT543DWR operate below 3.3 V, and what is the minimum VCC?

Yes, SN74LVT543DWR is fully characterized to operate down to 2.7 V VCC, supporting unregulated battery-powered systems. At VCC = 2.7 V, it maintains guaranteed VOL ≤ 0.5 V (IOL = 24 mA), VOH ≥ 2.4 V (IOH = –8 mA), and timing parameters including tPLH/tPHL ≤ 5.7 ns. The device retains bus-hold functionality, 5-V input tolerance, and latch/register operation across the entire 2.7–3.6 V range, with ICC dropping to 0.13 mA in 3-state mode.

Is SN74LVT543DWR pin-compatible with other packages in the LVT543 family?

SN74LVT543DWR (DW package) shares identical pinout and functionality with SN74LVT543DBR (DB package) and SN74LVT543PWR (PW package), as confirmed by TI's SCBS137D datasheet top-view diagrams and package option addendum. All three use the same 24-pin arrangement: A1–A8 on left, B1–B8 on right, with LEAB/OEAB/CEAB on top row and LEBA/OEBA/CEBA on bottom row. Mechanical dimensions differ, but electrical behavior, timing, and logic function are identical across DW, DB, and PW variants.