Texas Instruments SN74LVT543PWR

Overview

SN74LVT543 from Texas Instruments is a 3.3-V ABT octal registered transceiver with 3-state outputs, designed for bidirectional data flow between 3.3-V and 5-V systems. It features dual D-type latch sets (A↔B), independent latch-enable (LEAB/LEBA) and output-enable (OEAB/OEBA) controls, bus-hold inputs, and operates from 2.7 V to 3.6 V. It is used in mixed-voltage backplane interfaces and memory expansion subsystems.

For engineers reviewing the SN74LVT543 datasheet, SN74LVT543 pinout, SN74LVT543 application, or SN74LVT543 equivalent, key selection criteria include its 3.3-V ABT logic family compatibility, 24-pin TSSOP (PW) package, ±64 mA output drive, bus-hold input retention, and support for live insertion in hot-swap applications.

Technical Context

The SN74LVT543 implements two independent 8-bit registered transceiver channels using Advanced BiCMOS Technology (ABT), enabling simultaneous A-to-B and B-to-A data latching with separate control paths. Its architecture supports true bidirectional flow via CEAB/CEBA, LEAB/LEBA, and OEAB/OEBA inputs - each controlling direction, storage timing, and output enable independently.

It integrates bus-hold circuitry on all A and B data inputs to maintain valid logic states without external pullups, and features TTL-compatible 5-V tolerant inputs while powered at 3.3 V. Output ground bounce (VOLP) is specified < 0.8 V at VCC = 3.3 V, TA = 25°C, supporting noise-resilient operation in dense PCB layouts.

Key Specifications

Pinout & Package

SN74LVT543 is packaged in a 24-pin Thin Shrink Small-Outline (PW) package, 0.65 mm pitch, 7.8 mm × 4.4 mm body size, lead-free and RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVTH16245ADGGR and SN74ALVC164245DGGR, the SN74LVT543 uniquely combines octal bidirectional latching, bus-hold inputs, and 5-V-tolerant I/O in a compact 24-pin TSSOP - making it optimal for space-constrained, timing-sensitive mixed-voltage register interfaces where signal integrity and reduced BOM are priorities.

Availability

SN74LVT543 is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, memory expansion subsystems, hot-swap I/O modules, and backplane data interfaces requiring stable component supply and long-term lifecycle support.

Supply support for SN74LVT543 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 experience in high-reliability interface ICs.

The SN74LVT543 belongs to TI's ABT (Advanced BiCMOS Technology) logic family, engineered for low-voltage, high-speed, mixed-signal interfacing in industrial, telecom, and computing infrastructure applications.

FAQ

What voltage levels does the SN74LVT543 support on its inputs and outputs?

The SN74LVT543 accepts 5-V TTL input levels while operating from a 3.3-V VCC supply, and delivers 3.3-V CMOS-compatible outputs. Its inputs tolerate up to 5.5 V, and outputs are rated for 64 mA sink current and –32 mA source current at VCC = 3.3 V. This mixed-mode capability makes SN74LVT543 ideal for bridging legacy 5-V and modern low-voltage systems without external level shifters.

Does the SN74LVT543 include bus-hold circuitry, and how does it affect system design?

Yes, the SN74LVT543 integrates bus-hold circuitry on all 16 data I/O pins (A1–A8 and B1–B8), maintaining valid logic states on unused or floating inputs without external pullup/pulldown resistors. This feature reduces BOM count, saves PCB space, and improves reliability in systems with intermittent connections - a key advantage in backplane and hot-swap applications where SN74LVT543 is commonly deployed.

Can the SN74LVT543 be used in hot-swap or live-insertion systems?

Yes, the SN74LVT543 supports live insertion due to its controlled power-up behavior and bus-hold inputs. To ensure high-impedance outputs during power transitions, OEAB and OEBA should be tied to VCC through a pullup resistor (value determined by driver sink capability). This configuration prevents bus contention during insertion, making SN74LVT543 suitable for modular I/O systems and field-replaceable units where SN74LVT543 serves as the primary interface transceiver.

What is the operating temperature range and packaging for the SN74LVT543?

The SN74LVT543 is characterized for industrial operation from –40°C to +85°C and is offered in a 24-pin Thin Shrink Small-Outline (PW) package - 7.8 mm × 4.4 mm, 0.65 mm pitch, RoHS-compliant and green (no Sb/Br). This compact, surface-mount package supports high-density routing and automated assembly, aligning with modern PCB manufacturing practices for systems using SN74LVT543 in space-constrained designs.

How does the latch-enable functionality work in the SN74LVT543 for bidirectional data flow?

The SN74LVT543 uses separate latch-enable inputs (LEAB for A→B, LEBA for B→A): when low, the corresponding path is transparent; a low-to-high transition captures and holds data in the respective 8-bit latch. This allows independent, synchronous registration of data in either direction - essential for timing-critical applications like memory-mapped I/O or pipeline staging where SN74LVT543 ensures deterministic data capture aligned to system clocks or control edges.