Synchronous FIFO for bus buffering
The Texas Instruments SN74ACT7801-20FN is a synchronous FIFO memory organized 1Kx18 with a 20 ns access time. It provides a dedicated buffering stage for data streams that need to cross clock domains or absorb burst traffic without back-pressure stalling the bus. Typical applications include telecom line cards, data-acquisition front-ends, and DSP co-processor interfaces where the write and read clocks run independently.
20 ns access — what it buys the bus
The 20 ns access time sets the minimum cycle window for reading a word out of the FIFO.
RoHS non-compliance — BOM impact
This part is marked RoHS non-compliant. That means it contains lead (Pb) in the solder finish or die-attach above the exemption threshold. For a design that must ship under full RoHS, you will need an exemption letter or a compliant alternative. For legacy builds, military, or high-reliability programs that still allow tin-lead, it is business as usual.