Texas Instruments SN74LVTH16646DLR

Overview

SN74LVTH16646DLR from Texas Instruments is a 16-bit bus transceiver and register IC designed for 3.3-V V_CC operation with 5-V tolerant inputs/outputs, supporting mixed-mode signal interfacing between 3.3-V logic and legacy 5-V systems. It features dual 8-bit or single 16-bit bidirectional data flow, clocked storage on CLKAB/CLKBA rising edges, and real-time or stored-data multiplexing via SAB/SBA controls. Used in high-speed backplane and memory interface applications requiring hot-insertion support and bus-hold functionality.

For engineers reviewing the SN74LVTH16646DLR datasheet, SN74LVTH16646DLR pinout, SN74LVTH16646DLR application, or SN74LVTH16646DLR equivalent, this page delivers verified functional architecture, timing-critical switching parameters (t_PLH/t_PHL ≤ 4.7 ns at 3.3 V), hot-swap I_off and power-up 3-state behavior, and precise SSOP-56 package mapping - all essential for PCB layout, signal integrity analysis, and system-level bus arbitration design.

Technical Context

The SN74LVTH16646DLR implements a dual-register transceiver architecture with independent A/B port clocking (CLKAB/CLKBA), direction control (DIR), output enable (OE), and select controls (SAB/SBA) enabling four bus-management modes: real-time transfer, stored-data transfer, isolation with hold, and simultaneous A/B storage. Its ABT BiCMOS process ensures low static power (I_CC = 0.19 mA in disabled state) and robust noise immunity via distributed V_CC/GND pins and flowthrough layout.

It supports unregulated battery operation down to 2.7 V, tolerates 5.5-V inputs while powered at 3.3 V, and guarantees latch-up immunity >500 mA per JESD 17. Bus-hold circuitry eliminates external pull resistors on A/B data lines, and I_off protection prevents backflow during hot insertion when V_CC = 0.

Key Specifications

Pinout & Package

SN74LVTH16646DLR is housed in a 56-pin SSOP (Shrink Small Outline Package) with 0.5-mm pitch, 13.9 mm × 7.9 mm body size, and 1.2-mm max height - optimized for high-density PCB layouts with minimal trace stubs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVTH16646DLR, SN74LVC16646DGGR trades 5-V tolerance and drive strength for lower static power, while SN74ALVCH16646DLR offers higher clock rate but removes bus-hold - making SN74LVTH16646DLR uniquely balanced for mixed-voltage, hot-swap, and resistorless designs.

Availability

SN74LVTH16646DLR is available at Aetrix Electronics and suitable for memory interface buffering, FPGA-to-ASIC interconnect, and industrial backplane hot-swap applications requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for SN74LVTH16646DLR 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 expertise in high-reliability logic and interface solutions.

The SN74LVTH16646DLR belongs to TI's Widebus™ family of advanced bus-interface ICs, engineered specifically for high-speed, mixed-voltage, hot-pluggable system architectures in telecom infrastructure, industrial automation, and computing platforms.

FAQ

What is the maximum clock frequency supported by the SN74LVTH16646DLR?

The SN74LVTH16646DLR supports a maximum clock frequency of 150 MHz across its recommended operating range (V_CC = 2.7 V to 3.6 V). This specification is validated under load conditions of C_L = 50 pF and applies to both CLKAB and CLKBA inputs, enabling reliable high-speed register staging in synchronous bus systems.

Does the SN74LVTH16646DLR support 5-V input signals while operating at 3.3-V V_CC?

Yes, the SN74LVTH16646DLR accepts input voltages up to 5.5 V while powered at 3.3 V, allowing direct interfacing with 5-V TTL logic without external level-shifting components. This 5-V tolerance is explicitly guaranteed in the Absolute Maximum Ratings and Electrical Characteristics tables of the official datasheet SCBS698G.

How does the bus-hold feature of the SN74LVTH16646DLR eliminate external pull resistors?

The SN74LVTH16646DLR integrates active bus-hold circuitry on all A/B port inputs, providing ±500 µA dynamic hold current at V_CC = 3.6 V. This maintains unused or unterminated inputs at their last-valid logic state, removing the need for discrete pullup/pulldown resistors and simplifying PCB layout and BOM management.

Is the SN74LVTH16646DLR suitable for hot-insertion applications?

Yes, the SN74LVTH16646DLR is fully qualified for hot-insertion use via dual protection mechanisms: I_off circuitry limits current to ±100 µA when V_CC = 0, and power-up 3-state ensures outputs remain high-impedance during power ramp-up/down - both verified per JESD 78 and TI application reports on live-card insertion.

What package type and dimensions does the SN74LVTH16646DLR use?

The SN74LVTH16646DLR uses a 56-pin SSOP (Shrink Small Outline Package) with DL suffix, measuring 13.9 mm × 7.9 mm × 1.2 mm max height and 0.5-mm lead pitch. Its tape-and-reel packaging contains 1000 units per reel, and the pin 1 quadrant is Q1 per TI's tape orientation standard.