SN74ACT3651-30PCB

Overview

The SN74ACT3651 is a high-speed, low-power CMOS clocked FIFO memory featuring a 2048 × 36 dual-port SRAM array. It supports clock frequencies up to 67 MHz and provides fast access times of 11 ns. The device includes retransmit capability, allowing previously read data to be accessed again. Communication between ports utilizes two 36-bit mailbox registers with dedicated flags. Status flags including input-ready, output-ready, almost-full, and almost-empty are synchronized to their respective port clocks.

Feature Summary

• Supports asynchronous or coincident free-running clocks for independent Port A and Port B operations
• Includes synchronous read-retransmit capability for repeated data access from user-selected positions
• Features two 36-bit mailbox registers for command and control information transfer between ports
• Provides programmable almost-full and almost-empty flags with selectable offset values

Applications

• Buffering data transfers between microprocessors and buses with synchronous control
• Creating wider data paths by connecting multiple devices in parallel
• Expanding word depth for larger memory buffering requirements
• DSP-interface applications requiring programmable filtering

Procurement Notes

Verify the specific package variant required, as the SN74ACT3651 family includes both 120-pin Thin Quad Flat (PCB) and 132-pin Plastic Quad Flat (PQ) options. Confirm that the ordering suffix matches the desired physical footprint and pin configuration. Ensure compatibility with existing board layouts before procurement, as these packages are not interchangeable without design modification.

Selection Notes

Select this component when designing systems requiring high-speed data buffering between asynchronous domains. The ACT series offers low power consumption suitable for battery-operated or heat-sensitive environments. Consider the 11 ns access time and 67 MHz clock support for high-throughput applications. Verify that the 36-bit data width aligns with system bus requirements or allows for efficient parallel expansion.

Part Context

This part belongs to the SN74ACT logic family, utilizing low-power 0.8-μm Advanced CMOS technology. It is pin-to-pin compatible with the SN74ACT3631 and SN74ACT3641 models, facilitating direct upgrades or replacements within existing designs. The device is characterized for operation from 0°C to 70°C, covering standard commercial temperature ranges.

Replacement Considerations

The SN74ACT3651 is pin-to-pin compatible with the SN74ACT3631 and SN74ACT3641.