Texas Instruments SN74LVTH543PW

Overview

SN74LVTH543PW from Texas Instruments is an octal transceiver with dual-directional latched data flow, supporting mixed-mode 3.3-V V_CC operation with 5-V tolerant inputs and outputs. It features bus-hold on all data inputs, I_off for hot insertion, and operates down to 2.7 V. It is used in voltage-level translation between 3.3-V logic domains and legacy 5-V backplanes or peripheral buses.

For engineers reviewing the SN74LVTH543PW datasheet, SN74LVTH543PW pinout, SN74LVTH543PW application, or SN74LVTH543PW equivalent, this device serves as a bidirectional, latch-enabled bus interface for industrial control backplanes, test equipment I/O expansion, and FPGA-to-legacy-peripheral bridging where power sequencing robustness and input hold are critical.

Technical Context

The SN74LVTH543PW implements two independent sets of D-type transparent latches-one for A-to-B and one for B-to-A data flow-each controlled by dedicated latch-enable (LEAB/LEBA) and output-enable (OEAB/OEBA) signals. CEAB and CEBA enable direction-specific data capture and output activation.

It integrates active bus-hold circuitry on all A and B port inputs (±75 µA hold current at V_CC = 3 V), eliminating external pull resistors. I_off protection disables outputs during power-down (V_CC = 0), preventing backdrive current, while power-up 3-state ensures high-impedance outputs during V_CC ramp from 0 to 1.5 V.

Key Specifications

Pinout & Package

TSSOP-24 package (PW), 7.9 mm × 4.5 mm × 1.2 mm max height, 0.65 mm pitch, exposed metal pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVTH543PW, SN74LVC543APW sacrifices bus-hold and hot-insertion capability for lower static current, while SN74ALVCH162244DL trades latching and direction control for double the width and faster propagation-neither offers drop-in replacement due to pinout, control logic, or functional mismatch.

Availability

SN74LVTH543PW is available at Aetrix Electronics and suitable for industrial backplane interfaces, FPGA I/O expansion, automated test equipment fixtures, and embedded controller peripheral bridges requiring stable component supply across extended temperature ranges.

Supply support for SN74LVTH543PW 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 industrial-grade reliability validation.

The SN74LVTH543PW belongs to TI's LVTH logic family, engineered for robust mixed-voltage interfacing in harsh environments-designed specifically to replace obsolete TTL devices while maintaining pin-compatible layouts and backward-compatible timing.

FAQ

What is the operating voltage range for SN74LVTH543PW?

The SN74LVTH543PW operates from 2.7 V to 3.6 V on V_CC. Its inputs tolerate up to 7 V, enabling direct connection to 5-V TTL signals without external level shifters. This range supports unregulated battery supplies and accommodates typical 3.3-V rail tolerances in industrial systems. The device remains functional across the full −40°C to +85°C ambient temperature range specified for the TSSOP-PW package.

Does SN74LVTH543PW support hot insertion?

Yes, SN74LVTH543PW supports hot insertion via two integrated features: I_off circuitry disables outputs when V_CC = 0, preventing damaging backdrive current, and power-up 3-state holds all outputs in high-impedance until V_CC exceeds 1.5 V. These functions are verified per JESD78 and documented in the SCBS704F datasheet, making SN74LVTH543PW suitable for modular backplane and plug-in card applications.

How does bus-hold work on SN74LVTH543PW inputs?

SN74LVTH543PW integrates active bus-hold circuitry on all A and B port inputs, drawing ±500 µA (max) to maintain the last-valid logic state when inputs float. This eliminates the need for external 10-kΩ pullup or pulldown resistors. Bus-hold current is specified at V_CC = 3.6 V and VI = 0–3.6 V, and it functions independently of OE or CE states-ensuring stable inputs even during power transitions or idle periods.

What is the pinout configuration of SN74LVTH543PW?

SN74LVTH543PW uses a 24-pin TSSOP (PW) package with pin 1 in the top-left corner (index area). Per TI's PW0024A drawing, pins 1–8 are A1–A8 inputs, pins 9–16 and 21–24 form the 8-bit B port (bidirectional), pin 17 is CEAB, pin 18 is GND, pin 19 is V_CC, and pin 20 is CEBA. Control signals LEAB, OEAB, LEBA, and OEBA occupy pins 2, 3, 4, and 5 respectively-confirmed by the top-view diagram in SCBS704F.

Can SN74LVTH543PW replace older 74ACT or 74AS series transceivers?

SN74LVTH543PW is designed as a functional upgrade to 74ACT543 and 74AS543, offering identical 24-pin TSSOP/SOIC footprints, compatible control logic (CE/LE/OE), and enhanced features including bus-hold, I_off, and wider V_CC tolerance. While electrical parameters differ (e.g., lower VOLP, higher noise immunity), timing and DC specs meet or exceed legacy parts-making SN74LVTH543PW a drop-in replacement in most 5-V/3.3-V mixed-signal designs documented in TI application notes.