Texas Instruments SN74LVTH543DW

Overview

SN74LVTH543DW from Texas Instruments is an octal transceiver with dual-directional latched data flow, supporting mixed-mode 5-V/3.3-V interfacing. It features bus-hold on all data inputs, Ioff and power-up 3-state for hot insertion, and operates from 2.7 V to 3.6 V VCC. Used in backplane interface and legacy-to-low-voltage system bridging where level translation and latch-controlled data staging are required.

For engineers reviewing the SN74LVTH543DW datasheet, SN74LVTH543DW pinout, SN74LVTH543DW application, or SN74LVTH543DW equivalent, this page delivers verified functional identity, SOIC-24 package mapping, timing-critical enable/latch control behavior, bus-hold current specs, and validated alternative options for industrial bus interface designs.

Technical Context

The SN74LVTH543DW implements two independent sets of D-type transparent latches-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. CEAB and CEBA act as directional chip enables, requiring low assertion to activate respective data paths.

Its bus-hold circuitry provides ±500 µA dynamic hold current at 3.6 V, eliminating external pull resistors. Ioff limits off-state current to ±100 µA when VCC = 0, and power-up 3-state ensures outputs remain high-impedance during VCC ramp from 0 to 1.5 V.

Key Specifications

Pinout & Package

SN74LVTH543DW uses a 24-pin SOIC (DW) package with 300-mil body width, 0.65-mm lead pitch, and 1.2-mm max height per JEDEC MO-153. Pin 1 index area located at top-left corner with beveled edge marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVTH543DW, SN74LVC245APWR lacks latching and bus-hold, limiting its use in asynchronous staging; SN74LVCH16245ADGGR offers wider bus width but no per-octal latch control, making it unsuitable for independent A/B channel timing management.

Availability

SN74LVTH543DW is available at Aetrix Electronics and suitable for industrial backplane interface, legacy voltage bridging, hot-swappable module control, and test equipment signal routing requiring stable component supply and long-term manufacturability.

Supply support for SN74LVTH543DW 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 connectivity technologies with over 90 years of innovation in industrial and automotive electronics.

The SN74LVTH543DW belongs to TI's LVTH logic family, designed specifically for robust mixed-voltage system interfacing with emphasis on hot-plug safety, bus stability, and latch-controlled data staging in industrial control infrastructure.

FAQ

What is the primary function of the SN74LVTH543DW in a mixed-voltage system?

The SN74LVTH543DW serves as a bidirectional octal transceiver with independent latch and output enable controls for each direction, allowing it to bridge 5-V and 3.3-V logic domains without external level shifters. Its bus-hold circuitry stabilizes floating inputs, and Ioff protection prevents backdrive during power transitions - making SN74LVTH543DW ideal for reliable interconnection in hybrid voltage environments like industrial PLC backplanes.

Does the SN74LVTH543DW support hot insertion, and how is that implemented?

Yes, the SN74LVTH543DW supports hot insertion through two integrated features: Ioff circuitry limits off-state current to ±100 µA when VCC = 0, preventing damaging backflow; and power-up 3-state forces outputs into high-impedance during VCC ramp from 0 to 1.5 V. These mechanisms ensure SN74LVTH543DW remains electrically isolated and non-disruptive when inserted into a live 3.3-V bus - a key requirement for modular industrial hardware.

What are the timing implications of using the latch-enable (LE) versus output-enable (OE) pins on the SN74LVTH543DW?

On the SN74LVTH543DW, LEAB/LEBA control data capture transparency and storage mode - a low LE enables real-time pass-through, while a rising edge latches the current A or B bus state. OEAB/OEBA independently control driver activation - low enables output drivers, high places them in high-Z. This separation allows SN74LVTH543DW to stage data in latches while keeping outputs disabled until ready, enabling precise synchronization in test equipment or buffered bus arbitration.

Can the SN74LVTH543DW operate below 3.3 V, and what is the minimum functional VCC?

Yes, the SN74LVTH543DW is fully specified from 2.7 V to 3.6 V VCC. At 2.7 V, it maintains guaranteed VOL ≤ 0.5 V at IOL = 24 mA and VOH ≥ 2.4 V at IOH = −8 mA, with bus-hold current remaining effective. This 2.7-V minimum supports unregulated battery-powered systems and brown-out resilience - a design feature confirmed across all recommended operating conditions in the SN74LVTH543DW datasheet.

How does the bus-hold feature on the SN74LVTH543DW eliminate the need for external resistors?

The SN74LVTH543DW integrates active bus-hold circuitry on all A and B port inputs, delivering ±500 µA dynamic hold current at 3.6 V to maintain valid logic levels on undriven or floating lines. Because this internal circuit actively reinforces the last valid state, external pullup or pulldown resistors become redundant - reducing component count, board space, and potential noise coupling. This behavior is intrinsic to SN74LVTH543DW and requires no configuration or external components to activate.