Texas Instruments SN74LVCH16543AZQLR

Overview

SN74LVCH16543AZQLR from Texas Instruments is a 16-bit registered transceiver with 3-state outputs, designed for bidirectional data flow between two 8-bit buses or as a single 16-bit transceiver. It operates from 1.65 V to 3.6 V, accepts 5.5-V-tolerant inputs, delivers 5.4-ns max propagation delay at 3.3 V, and supports partial-power-down via Ioff. It is used in mixed-voltage system interfacing, such as 3.3-V logic-to-5-V peripheral bridging in industrial control backplanes.

For engineers reviewing the SN74LVCH16543AZQLR datasheet, SN74LVCH16543AZQLR pinout, SN74LVCH16543AZQLR application, or SN74LVCH16543AZQLR equivalent, key selection criteria include its dual 8-bit latch-enable and output-enable control per direction, bus-hold inputs eliminating external resistors, and verified 5.5-V input tolerance enabling safe 5-V signal reception on 3.3-V rails.

Technical Context

The SN74LVCH16543AZQLR implements two independent 8-bit registered transceiver sections (A↔B), each with dedicated CE, LE, and OE controls for precise timing isolation. Its latch-enable logic enables transparent-to-latched transition on rising edge, while 3-state outputs are disabled independently per direction using OEAB/OEBA.

It integrates Ioff circuitry to disable outputs during power-down, preventing backflow current, and includes active bus-hold on all A/B data inputs-retaining valid logic states without external pullups. Input voltage tolerance up to 5.5 V allows direct connection to 5-V TTL outputs while powered from 3.3-V supplies.

Key Specifications

Pinout & Package

VFBGA package (ZQL), 56-pin, 3.5 mm × 4.5 mm, 0.5-mm pitch, Pb-free, moisture sensitivity level 1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC16245ADGGR and SN74AVC16T245DGGR, the SN74LVCH16543AZQLR uniquely provides per-direction registered latching and independent output enable - essential for synchronous data capture in buffered memory-mapped I/O or time-critical control loops.

Availability

SN74LVCH16543AZQLR is available at Aetrix Electronics and suitable for industrial backplane interfaces, automotive body control modules, programmable logic interconnects, and test equipment signal conditioning requiring stable component supply and long-term lifecycle support.

Supply support for SN74LVCH16543AZQLR 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 decades of experience in high-reliability logic and interface solutions.

The SN74LVCH16543AZQLR belongs to TI's Widebus™ family of advanced CMOS logic devices, engineered specifically for high-speed, low-voltage, mixed-signal system interfacing in industrial, automotive, and communications infrastructure.

FAQ

What is the maximum operating temperature range for the SN74LVCH16543AZQLR?

The SN74LVCH16543AZQLR is rated for operation from –40°C to +85°C ambient temperature, meeting industrial-grade thermal requirements. This range is validated across all electrical parameters in the datasheet, including propagation delay, output drive strength, and bus-hold current, ensuring reliable performance in factory automation and outdoor control enclosures where ambient extremes occur.

Does the SN74LVCH16543AZQLR support hot insertion or live board swapping?

Yes, the SN74LVCH16543AZQLR supports partial-power-down operation via its Ioff feature, which disables outputs and blocks current backflow when VCC = 0 V. This makes it suitable for hot-plug applications such as modular I/O cards in programmable logic controllers, provided OE is held high (via pullup) during insertion to maintain high-Z outputs until power stabilizes.

Can the SN74LVCH16543AZQLR be used as a level shifter between 1.8-V and 5-V logic domains?

The SN74LVCH16543AZQLR accepts 5.5-V inputs while operating from 1.65–3.6-V VCC, making it ideal for translating 5-V signals down to 3.3-V or 2.5-V logic. However, it does not support true bidirectional level shifting below 1.65 V - for 1.8-V domain interfacing, use VCC = 1.8 V and verify VOL/VOH margins against downstream thresholds; it cannot drive 5-V-high signals from a 1.8-V supply.

How does the bus-hold function interact with the output-enable (OE) control in the SN74LVCH16543AZQLR?

The bus-hold circuitry in the SN74LVCH16543AZQLR is part of the input stage and remains fully active regardless of OE state - it holds unused A or B data inputs at valid logic levels even when outputs are disabled. This eliminates need for external biasing and ensures stable inputs during configuration, reset, or tri-state periods without affecting OE-controlled output behavior.

What is the recommended power-up sequence for reliable operation of the SN74LVCH16543AZQLR?

TI recommends tying OEAB and OEBA to VCC through ≥10-kΩ pullup resistors to ensure outputs remain in high-impedance state during power ramp-up. VCC must stabilize before applying input signals; no strict sequencing is required between VCC and control inputs, but CE/LE/OE should be held inactive (high) until VCC reaches ≥1.5 V to prevent undefined latch behavior per datasheet Section 6.2.