Texas Instruments SN74LVCH16646ADGGR

Overview

SN74LVCH16646ADGGR 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 signal operation (5-V-tolerant inputs with 3.3-V VCC), features bus-hold on all data inputs, Ioff partial-power-down protection, and delivers 5.7 ns max propagation delay at 3.3 V - enabling high-speed bidirectional data routing in memory interfaces and FPGA/ASIC interconnects.

For engineers reviewing the SN74LVCH16646ADGGR datasheet, SN74LVCH16646ADGGR pinout, SN74LVCH16646ADGGR application, or SN74LVCH16646ADGGR equivalent, key selection criteria include its dual 8-bit register-controlled transceiver architecture, 56-pin TSSOP package, 3.3-V-compatible 5-V-tolerant I/O, and support for real-time or stored-data transfer between A/B buses under independent DIR/OE/SAB/SBA control.

Technical Context

The SN74LVCH16646ADGGR integrates two independent 8-bit transceiver channels, each with D-type flip-flops clocked on CLKAB/CLKBA rising edges, and configurable select logic (SAB/SBA) that eliminates multiplexer glitches during transitions between transparent and registered data paths. Its Ioff circuitry disables outputs during power-down to prevent backflow current, while bus-hold inputs eliminate external pull resistors.

It operates across 1.65–3.6 V VCC, accepts input voltages up to 5.5 V on all ports, and guarantees timing performance including 150 MHz max clock frequency, 3.2 ns min setup time (at 3.3 V), and 0.3 ns max hold time - validated over –40°C to +85°C ambient temperature.

Key Specifications

Pinout & Package

TSSOP-56 (DGG) package, 13.9 mm × 6.1 mm × 1.2 mm max height, lead-free NiPdAu finish, MSL Level-1, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC16646ADGGR, the SN74LVCH16646ADGGR adds 5-V tolerance and bus-hold - reducing external components and improving robustness in noisy environments; versus 74ALVCH16646GRE4, it trades 1.5 ns faster tpd for broader voltage operation and superior ESD ratings.

Availability

SN74LVCH16646ADGGR is available at Aetrix Electronics and suitable for memory interface buffering, FPGA-to-ASIC bridging, industrial PLC backplanes, and ATE signal routing requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74LVCH16646ADGGR 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 expertise in high-reliability interface ICs for industrial, automotive, and communications markets.

The SN74LVCH16646ADGGR belongs to TI's Widebus™ family of advanced bus-interface devices, engineered specifically for high-speed, low-voltage, mixed-signal system interconnects requiring robust voltage translation and glitch-free data staging.

FAQ

What is the maximum clock frequency supported by the SN74LVCH16646ADGGR?

The SN74LVCH16646ADGGR supports a maximum clock frequency of 150 MHz across its recommended operating range (1.65 V to 3.6 V VCC, –40°C to +85°C). This rating is verified per TI's SCAS318K datasheet timing specifications and applies to both CLKAB and CLKBA inputs under load conditions defined in Figure 2 (CL = 30–50 pF, VIH/VIL thresholds met). The device achieves this using optimized internal logic paths and low-propagation-delay design.

Does the SN74LVCH16646ADGGR require external pull-up or pull-down resistors on its data lines?

No, the SN74LVCH16646ADGGR does not require external pull-up or pull-down resistors on its A1–A8 or B1–B8 data inputs because it integrates active bus-hold circuitry on all 32 data pins. This feature maintains unused or undriven inputs at valid logic states, eliminating floating nodes. Using external resistors with enabled bus-hold is explicitly discouraged per TI's datasheet guidance.

Can the SN74LVCH16646ADGGR be used in a system where some ICs operate at 5 V and others at 3.3 V?

Yes, the SN74LVCH16646ADGGR is explicitly designed for mixed-voltage operation: its inputs accept voltages up to 5.5 V regardless of VCC (1.65–3.6 V), and its outputs swing to valid 3.3-V logic levels. This allows direct connection between 5-V legacy peripherals and 3.3-V controllers without external level shifters - a core capability confirmed in the "Mixed-Mode Signal Operation" feature list and functional description.

What is the purpose of the Ioff feature in the SN74LVCH16646ADGGR?

The Ioff feature in the SN74LVCH16646ADGGR disables all outputs when VCC = 0 V, preventing damaging current backflow through the device during partial power-down or hot-swap events. This is critical in modular systems like PLC backplanes or server blades where boards may be inserted/removed while other sections remain powered. The Ioff specification (±10 µA max) is guaranteed per JESD78 testing and documented in the Electrical Characteristics table.

How does the SN74LVCH16646ADGGR handle simultaneous switching noise (SSN)?

The SN74LVCH16646ADGGR mitigates simultaneous switching noise via low ground bounce (VOLP < 0.8 V typical at 3.3 V) and low output undershoot (VOHV > 2 V typical), both measured at TA = 25°C. Its distributed VCC/GND pin layout (eight each) and optimized output driver design reduce transient current spikes. These characteristics are validated in the "Electrical Characteristics" section and support stable operation in high-density PCB layouts.