Texas Instruments SN74ALVCH16646DL

Overview

SN74ALVCH16646DL from Texas Instruments is a 16-bit bus transceiver and register with 3-state outputs, designed for bidirectional data flow control between two 8-bit buses (A and B) in 1.65-V to 3.6-V systems. It supports real-time or registered data transfer, features dual clock inputs (CLKAB/CLKBA), independent direction (DIR) and output-enable (OE) controls, and bus-hold circuitry eliminating external pullup resistors - used in high-density memory interface and FPGA I/O bridging applications.

For engineers reviewing the SN74ALVCH16646DL datasheet, SN74ALVCH16646DL pinout, SN74ALVCH16646DL application, or SN74ALVCH16646DL equivalent, key selection criteria include its 56-pin SSOP (DL) package, ±24 mA drive strength at 3 V, 150 MHz max clock frequency, bus-hold input retention, and dual-register architecture enabling simultaneous A/B storage or selective real-time multiplexing.

Technical Context

The SN74ALVCH16646DL implements two independent 8-bit transceiver/register blocks, each with dedicated DIR, OE, CLKAB/CLKBA, and SAB/SBA select controls. Its EPIC™ submicron CMOS process enables low-voltage operation (1.65–3.6 V) while maintaining TTL-compatible logic thresholds and robust ESD protection (>2000 V HBM).

It operates in four distinct modes: real-time bidirectional transfer (OE low + DIR set), stored-data transfer (SAB/SBA asserted), isolation with register hold (OE high), and concurrent A/B register capture (both clocks active). All data inputs remain enabled regardless of OE state, supporting transparent data latching on every clock edge.

Key Specifications

Pinout & Package

SN74ALVCH16646DL uses a 56-pin Shrink Small-Outline Package (SSOP, DL), 13.9 mm × 7.4 mm body, 0.635 mm pitch, 1.2 mm max height, JEDEC MO-194 compliant, with exposed metal not present and no thermal pad.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74ALVCH16646DL, SN74ALVCH162245DL trades register functionality for lower latency and cost, while SN74LVC16646DL extends voltage range and drive strength at the expense of bus-hold - making SN74ALVCH16646DL optimal for registered, self-biasing, industrial 1.65–3.6 V bus management.

Availability

SN74ALVCH16646DL is available at Aetrix Electronics and suitable for memory interface buffering, FPGA-to-ASIC bridging, and industrial PLC I/O expansion requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for SN74ALVCH16646DL 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 and widebus architectures.

The SN74ALVCH16646DL belongs to TI's Widebus™ family - engineered specifically for high-speed, low-voltage bidirectional bus management in space-constrained industrial, computing, and communications systems.

FAQ

What is the primary function of the SN74ALVCH16646DL?

The SN74ALVCH16646DL is a 16-bit bus transceiver with integrated registers and 3-state outputs. It enables bidirectional data transfer between two 8-bit buses (A and B), supports real-time or clocked (registered) operation, and provides independent control of direction, output enable, and data source selection - making it ideal for synchronous bus interfacing in FPGAs, processors, and memory subsystems. The SN74ALVCH16646DL integrates bus-hold circuitry to eliminate external pull resistors on floating inputs.

Does the SN74ALVCH16646DL support mixed-voltage operation?

Yes, the SN74ALVCH16646DL operates from 1.65 V to 3.6 V, allowing seamless integration between 1.8 V, 2.5 V, and 3.3 V logic domains without level-shifting components. Its input thresholds scale with VCC (e.g., VIH = 0.65×VCC at 1.65 V), and output drive strength adjusts accordingly (±24 mA at 3 V). This makes the SN74ALVCH16646DL well-suited for voltage-scalable designs such as portable instrumentation and multi-rail embedded controllers.

How does the bus-hold feature work on the SN74ALVCH16646DL?

The SN74ALVCH16646DL includes active bus-hold circuitry on all A and B data inputs, which detects and maintains the last-valid logic state (high or low) when an input floats - eliminating the need for external pullup or pulldown resistors. At 3 V, the bus-hold current is ±75 µA, sufficient to override typical leakage currents. This feature reduces BOM cost, saves PCB space, and improves reliability in systems with unconnected or intermittently driven bus lines - a key advantage of the SN74ALVCH16646DL in modular or field-upgradeable hardware.

Can the SN74ALVCH16646DL be used for both 8-bit and 16-bit configurations?

Yes, the SN74ALVCH16646DL is architecturally split into two independent 8-bit sections (1A/1B and 2A/2B), each with dedicated DIR, OE, CLK, and Sx control inputs. This allows flexible use as either two separate 8-bit transceivers - for example, isolating address and data buses - or as a unified 16-bit unit by tying control signals together. The SN74ALVCH16646DL's pinout and internal partitioning make it adaptable to varying data-width requirements without redesigning the PCB layout.

What is the significance of the DL package designation for SN74ALVCH16646DL?

The "DL" suffix denotes a 56-pin Shrink Small-Outline Package (SSOP) with 0.635 mm lead pitch, 13.9 mm × 7.4 mm body size, and 1.2 mm maximum height - JEDEC MO-194 compliant. Unlike TSSOP (DGG) or TVSOP (DGV) variants, the DL package uses tube packaging (20 units/tube) rather than tape-and-reel, and is optimized for prototyping, low-volume production, and manual assembly. The SN74ALVCH16646DL's DL package offers mechanical robustness and thermal performance suitable for industrial environments where reflow profile control is less stringent.