Obsolete — sourcing this FIFO on the spot market
We source these through our Shenzhen and global spot network — date codes vary, but we screen every reel or tray for authenticity and electrical continuity before it ships.
This is a Cypress CY7C-series synchronous FIFO organized 1K words deep by 18 bits wide — 18K total bits. The 66.7 MHz data rate means a 15 ns minimum clock period; every read or write cycle needs that much setup-to-clock edge margin. The 11 ns access time is the delay from the rising clock edge to valid data on the outputs — budget that into your bus timing closure, especially if you're cascading multiple FIFOs for depth expansion.
Package and temperature — commercial range, 64-LQFP
Housed in a 64-LQFP with a 14x14 mm body — surface-mount, fine-pitch, no exposed pad.
Retransmit and programmable flags — design-in details
This FIFO supports retransmit capability — you can reset the internal read pointer back to the first unread word without a full FIFO reset, useful for packet retry in networking or buffer replay in test equipment. Programmable flags let you set almost-full/almost-empty thresholds via the flag-programming pins, so the host controller gets an early warning before overflow or underflow. No FWFT (First-Word Fall-Through) support — the first word written does not appear on the outputs until the first read strobe; if your pipeline expects FWFT behavior, you'll need a different FIFO architecture.
Current draw and expansion
Maximum supply current is 30 mA at full 66.7 MHz operation — roughly 100 mW at 3.3 V, so no special thermal management needed inside a commercial-temperature chassis. Depth and width expansion is supported via the chip-select and expansion-out pins; multiple CY7C4225V-15ASXC devices can be cascaded to build wider (x36, x54) or deeper (2K, 4K) buffers without external glue logic, as long as the combined propagation delays stay within the clock period.