CY7C4251V-25AXC

FIFOs Memory Overview

The CY7C4251V-25AXC is a low-voltage, high-speed synchronous FIFO memory with an 8K x 9 organization. It operates at a maximum frequency of 40 MHz with a minimum cycle time of 25 ns and a data access time of 22 ns. The device functions on a 3.3 V supply with active current of 20 mA and supports 5 V-tolerant inputs. It features independent read and write clocks, programmable Almost Empty/Full flags, and is housed in a 32-pin Pb-Free TQFP package.

FIFOs Memory Feature Summary

• Supports fully asynchronous simultaneous read and write operations using independent clock domains.
• Includes programmable Almost Empty and Almost Full status flags for precise buffer management.
• Features 5 V-tolerant inputs to facilitate integration into mixed-voltage systems.

FIFOs Memory Applications

• High-speed data acquisition buffering
• Multi-processor interface synchronization
• Communications system buffering

FIFOs Memory Procurement Notes

Verify the specific speed grade suffix (e.g., -25) matches the required timing specifications. Confirm the package type corresponds to the A32 designation for the 32-lead Pb-Free Thin Quad Flatpack. Ensure the component meets the commercial operating temperature range requirements for the intended application environment.

FIFOs Memory Selection Notes

Select this model when an 8K depth and 9-bit width are required for synchronous buffering. The -25 speed grade provides a 40 MHz operational limit suitable for moderate-speed interfaces. Consider the 5 V tolerance if interfacing with legacy logic levels without additional level shifting circuitry.

FIFOs Memory Part Context

This component belongs to the CY7C42X1V family of low-voltage synchronous FIFOs manufactured by Cypress Semiconductor. The family includes variants ranging from 64x9 to 8Kx9 depths. The CY7C4251V represents the highest density option within this specific series, offering substantial buffering capacity for parallel data streams.

FIFOs Memory Replacement Considerations

CY7C4251V-15AXC: Offers faster 15 ns cycle time but requires verification of power and thermal constraints.

FIFOs Memory FAQ

How is the programmable flag offset configured?

The offset registers are programmed by holding WEN2/LD LOW during reset and using subsequent clock cycles to write data to the LSB and MSB registers for both empty and full conditions.

What happens to the outputs when the FIFO is empty?

When the Empty Flag (EF) is LOW, read operations are inhibited. The outputs maintain the data of the last valid read or go to a high-impedance state if Output Enable is asserted.