Texas Instruments SN74LVCH16646ADLR

Overview

SN74LVCH16646ADLR from Texas Instruments is a 16-bit bus transceiver and register with 3-state outputs, designed for 1.65 V to 3.6 V operation. It supports mixed-mode signaling (5-V-tolerant inputs with 3.3-V VCC), delivers 5.7 ns max propagation delay at 3.3 V, and integrates bus-hold circuitry and Ioff partial-power-down protection. It enables bidirectional data flow between A/B buses in industrial control backplanes and memory-mapped peripheral interfaces.

For engineers reviewing the SN74LVCH16646ADLR datasheet, SN74LVCH16646ADLR pinout, SN74LVCH16646ADLR application, or SN74LVCH16646ADLR equivalent, key selection criteria include 56-pin SSOP package compatibility, dual 8-bit register-controlled transceiver operation, 3.3-V logic-level translation capability, and support for real-time or stored-data transfer modes without external pull resistors.

Technical Context

The SN74LVCH16646ADLR implements two independent 8-bit transceiver/register blocks, each with dedicated clock (CLKAB/CLKBA), direction (DIR), output-enable (OE), and select (SAB/SBA) controls. Its D-type flip-flops latch A- or B-bus data on low-to-high clock transitions, enabling synchronous storage and multiplexed output routing.

It features true 5-V-tolerant inputs (VI up to 5.5 V) while operating from 1.65–3.6 V VCC, allowing seamless interfacing between legacy 5-V logic and modern low-voltage systems. The integrated bus-hold circuitry maintains valid logic states on undriven inputs, eliminating external biasing components.

Key Specifications

Pinout & Package

SN74LVCH16646ADLR uses a 56-pin SSOP (DL) package with 0.5-mm lead pitch, 13.9 mm × 7.9 mm body size, and 1.2-mm maximum height. Pin 1 is located at top-left corner of the package, marked by a beveled edge or dot.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVCH16646ADLR, SN74LVC16646A omits critical mixed-voltage and power-management features, while 74ALVCH16646 sacrifices low-voltage operation and 5-V tolerance-making SN74LVCH16646ADLR the only option supporting full 1.65–3.6 V range with 5-V input safety and Ioff protection.

Availability

SN74LVCH16646ADLR is available at Aetrix Electronics and suitable for industrial backplane interfaces, memory-mapped peripheral bridges, and hot-swappable module interconnects requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for SN74LVCH16646ADLR 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 industrial and automotive IC design.

The SN74LVCH16646ADLR belongs to TI's Widebus™ family of advanced bus-interface devices, engineered specifically for high-speed, mixed-voltage parallel bus management in programmable logic, microprocessor, and FPGA-based systems.

FAQ

What is the maximum clock frequency supported by SN74LVCH16646ADLR?

The SN74LVCH16646ADLR supports a maximum clock frequency of 150 MHz under recommended operating conditions (VCC = 3.3 V, TA = 25°C). This rating is confirmed in the Timing Requirements table of the official datasheet (SCAS318K), where fclock min/max values are specified across VCC ranges. The device achieves this performance while maintaining 5.7 ns max propagation delay and meeting setup/hold time requirements.

Does SN74LVCH16646ADLR require external pull-up resistors on its data lines?

No, SN74LVCH16646ADLR does not require external pull-up or pull-down resistors on its A or B data inputs because it integrates active bus-hold circuitry. This feature maintains valid logic states on undriven or floating inputs, as explicitly stated in the Features and Description sections of the datasheet. Using external resistors with bus-hold enabled is discouraged and may cause contention or increased power draw.

Can SN74LVCH16646ADLR operate safely when interfaced with 5-V logic signals?

Yes, SN74LVCH16646ADLR can safely interface with 5-V logic signals: its inputs accept voltages up to 5.5 V regardless of VCC level (1.65–3.6 V), enabling direct connection to 5-V TTL or CMOS outputs. This mixed-mode capability is documented in the Features list and Absolute Maximum Ratings table, and is central to its use in voltage-translation applications without external level shifters.

What package type and dimensions does SN74LVCH16646ADLR use?

SN74LVCH16646ADLR uses a 56-pin SSOP (Shrink Small Outline Package) with drawing code DL, measuring 13.9 mm × 7.9 mm with 0.5-mm lead pitch and 1.2-mm maximum height. This is confirmed in the Ordering Information table and Package Outline drawing (DGG0056A reference applies to DGG; DL package outline is documented in TI's SC package resource linked in the datasheet).

How does the Ioff feature function in SN74LVCH16646ADLR during partial power-down?

The Ioff feature in SN74LVCH16646ADLR disables output drivers and limits off-state leakage current to ±10 µA when VCC = 0 V, preventing damaging back-current flow through the device during partial power-down sequences. This behavior is verified in the Electrical Characteristics table (Ioff parameter) and described in the Description section as enabling safe hot-swap and power-gated system operation.