66.7 MHz synchronous FIFO — what the timing buys you
The CY7C4241V-15AXCT is a Cypress (now Infineon) synchronous FIFO with a 66.7 MHz data rate and 11 ns access time. In a synchronous FIFO, the read and write clocks run free-running; the 11 ns access time means the first word appears on the bus 11 ns after the read clock edge, giving the receiving logic a setup window of roughly 4 ns at 66.7 MHz (15 ns period minus 11 ns). That is tight but workable for 3.3 V CMOS inputs with typical 2 ns setup requirements. The 36K (4K x 9) organization suits byte-wide data paths with a parity bit — think telecom framers, DSP ping-pong buffers, or PCI target FIFOs where the extra bit carries an out-of-band flag.
Obsolete — no direct replacement on record
For existing BOM lines, sourcing runs through independent distribution — verified surplus or new-old-stock lots, quoted against an RFQ with traceability documentation.
Not rated for motor drives, outdoor base stations, or under-hood automotive — those would need an industrial or automotive-grade FIFO in a wider temp package.
Package and supply — board-fit checklist
32-TQFP (7x7 mm) surface-mount package. Maximum supply current is 20 mA. The part supports depth and width expansion (cascading multiple devices for deeper or wider buffers) and has programmable flags. No FWFT (First-Word Fall-Through) support; the first read after a write requires the 11 ns access time before valid data appears.