The SN74ALS646DW from Texas Instruments is a high-performance, octal bus transceiver and register designed to provide bidirectional communication between data buses. This integrated circuit is part of the Advanced Low-Power Schottky (ALS) series, which is known for combining the low power of standard CMOS with the speed of Schottky TTL devices.

Key Features

• Octal Bidirectional Transceiver: The device features eight bidirectional data lines that allow for easy data transfer in either direction between two separate buses.
• Integrated D-Type Latches: Each data line is equipped with a D-type latch that provides temporary data storage and presents data on the bus during the enabled state.
• Bus Hold on Data Inputs: The SN74ALS646DW eliminates the need for external pull-up resistors by providing a bus hold feature, which retains the last data presented on the inputs when the control enable is inactive.
• Separate Input-Output Enable Controls: The device includes separate control lines for input and output enable functions, offering greater flexibility in bus management.
• Wide Operating Temperature Range: The transceiver operates over a broad temperature range, making it suitable for industrial applications.
• Direct Replacement: It is designed to be a direct replacement for the SN74AS646 and SN74ALS646 devices, providing an upgrade path for systems using these older parts.

Applications

With its robust feature set, the SN74ALS646DW is ideal for a variety of applications where data must be transferred or temporarily stored. Common applications include:

• Bus interface in microprocessor or microcontroller-based systems
• Data communication systems
• Buffer memory address and data buses
• Peripheral driver or receiver in computing systems

Technical Specifications

The SN74ALS646DW is housed in a 24-pin wide-body SOIC package and operates on a 5V power supply. It features a typical propagation delay time of 5.5 ns, ensuring fast response for high-speed applications. The device also has a typical power dissipation of 40 mW, which contributes to its efficiency in power-sensitive designs.