Texas Instruments SN74LVTH16646DL

Overview

SN74LVTH16646DL 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 and 5-V systems. It features dual 8-bit bidirectional data paths, clocked storage (CLKAB/CLKBA), direction control (DIR), output enable (OE), and select control (SAB/SBA) for real-time or stored data routing - used in high-speed backplane and motherboard bus isolation applications.

For engineers reviewing the SN74LVTH16646DL datasheet, SN74LVTH16646DL pinout, SN74LVTH16646DL application, or SN74LVTH16646DL equivalent, key selection criteria include its 56-pin SSOP package, 150-MHz maximum clock frequency, bus-hold inputs eliminating external resistors, I_off support for hot insertion, and ±100 µA power-up 3-state behavior under V_CC ramp conditions.

Technical Context

This device implements a flowthrough architecture with distributed V_CC/GND pins to minimize switching noise and supports four bus-management functions: real-time A↔B transfer, storage of A/B data independently or jointly, and selective routing of stored vs. transparent data using glitch-free SAB/SBA logic. Its ABT BiCMOS process enables 2.7–3.6-V operation while maintaining TTL-compatible input thresholds and 5-V I/O tolerance.

The SN74LVTH16646DL integrates active bus-hold on all A/B data inputs (±75 µA hold current at V_CC = 3 V), I_off protection disabling outputs during power-down, and power-up 3-state to prevent bus conflicts - all verified per JESD 17 latch-up (>500 mA) and JESD 22 ESD standards (2000-V HBM, 200-V MM).

Key Specifications

Pinout & Package

SN74LVTH16646DL uses a 56-pin Shrink Small Outline Package (SSOP-DL) 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 thermal impedance θ_JA = 56°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit registered transceiver applications.

Compared with SN74LVC16646DL and SN74ALVCH16646DL, the SN74LVTH16646DL uniquely combines 5-V I/O tolerance, I_off-enabled hot insertion, and bus-hold - making it the only option among the three for robust mixed-voltage backplane isolation without external components.

Availability

SN74LVTH16646DL is available at Aetrix Electronics and suitable for industrial backplane interfaces, FPGA-to-memory bridges, telecom line card isolation, and automated test equipment requiring stable component supply across extended temperature ranges (−40°C to 85°C).

Supply support for SN74LVTH16646DL 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 high-reliability industrial and automotive electronics.

The SN74LVTH16646DL belongs to TI's Widebus™ family of advanced bus-interface ICs, engineered specifically for high-speed, mixed-voltage system interconnects in telecommunications, computing, and industrial automation.

FAQ

What is the operating voltage range for SN74LVTH16646DL?

The SN74LVTH16646DL operates from 2.7 V to 3.6 V on V_CC, with input and output pins rated for −0.5 V to 7 V - enabling direct interfacing with 5-V logic families without level shifters. This 5-V tolerance is confirmed in the Absolute Maximum Ratings table and supported by VI = 5.5 V test conditions in the Electrical Characteristics section.

Does SN74LVTH16646DL support hot insertion?

Yes, SN74LVTH16646DL supports hot insertion via two integrated features: I_off circuitry disables outputs when V_CC = 0 V to prevent damaging back-current, and power-up 3-state holds outputs high-impedance during power ramp-up. Both are explicitly documented in the Features list and validated per JESD 22 ESD and JESD 17 latch-up standards.

How does the bus-hold feature work on SN74LVTH16646DL?

The SN74LVTH16646DL includes active bus-hold circuitry on all A/B data inputs, maintaining unused or undriven pins at valid logic levels without external pullup/pulldown resistors. Its hold current is ±75 µA at V_CC = 3 V (Electrical Characteristics table), and TI explicitly warns against combining bus-hold with external resistors due to potential contention.

What package type is SN74LVTH16646DL supplied in?

SN74LVTH16646DL is supplied in a 56-pin Shrink Small Outline Package (SSOP) with DL suffix, measuring 13.9 mm × 7.9 mm with 0.5-mm lead pitch and 1.2-mm max height. Package dimensions, thermal data (θ_JA = 56°C/W), and PCB layout guidelines are published in TI's official DL package drawing and Package Option Addendum.

Can SN74LVTH16646DL be used as two independent 8-bit transceivers?

Yes, SN74LVTH16646DL can operate as two independent 8-bit transceivers using separate DIR, OE, CLKAB/CLKBA, and SAB/SBA controls for each half (1xx and 2xx signal groups). The Functional Description confirms this mode, and Figure 1 illustrates isolated A/B data paths with independent storage and routing capabilities.