SN74ACT7881-20PN

FIFOs Memory Overview

The SN74ACT7881-20PN is a synchronous first-in, first-out memory device organized as 1024 words by 18 bits. It operates with a supply voltage range of 4.5 V to 5.5 V and supports data rates up to 50 MHz. The component features independent asynchronous inputs and outputs, allowing read and write operations to be synchronized to separate system clocks. It provides fast access times of 13 ns maximum and includes programmable status flags for buffer management.

FIFOs Memory Feature Summary

• Supports independent read and write clock synchronization for asynchronous bus interfacing
• Includes programmable almost-full/almost-empty flag with user-defined or default offset values
• Provides half-full, input-ready, and output-ready status indicators for flow control
• Enables expansion in both word width and word depth through parallel or serial chaining

FIFOs Memory Applications

• Synchronous FIFO buffering between asynchronous data buses
• Data rate matching and clock domain crossing in digital systems
• Parallel data storage and retrieval in high-speed logic circuits
• Expandable memory arrays for wide-bus interface applications

FIFOs Memory Procurement Notes

Verify the specific -20 speed grade suffix against current Texas Instruments documentation to confirm timing parameters. Confirm package integrity for the 80-pin shrink quad flat configuration. Check for obsolescence status and lead-free compliance requirements prior to ordering. Ensure design compatibility with recommended operating conditions.

FIFOs Memory Selection Notes

Select this component when 18-bit word width and 1024-word depth are required. Choose the -20 variant if system timing allows up to 50 MHz operation. Consider the PN package for surface-mount assembly needs. Evaluate expansion capabilities if deeper or wider memory structures are necessary for the application design.

FIFOs Memory Part Context

This part belongs to the SN74ACT7881 family of clocked FIFO memories within the Widebus product line. It shares pinout compatibility with related models such as the SN74ACT7882 and SN74ACT7884. The device utilizes ACT logic technology for standard 5-V CMOS operation. It is designed for high-performance data buffering in complex digital architectures.

FIFOs Memory Replacement Considerations

SN74ACT7881-15FN

FIFOs Memory FAQ

How is the almost-full/almost-empty flag boundary defined?

The boundary is defined by an offset value (X) programmed during the reset cycle using the DAF pin and data inputs, or it defaults to 256.

What is the function of the WRTEN1 and WRTEN2 pins?

These pins must be held high before the rising edge of the write clock to enable writing data into the FIFO memory.