66.7 MHz synchronous FIFO — what the data rate means for the bus
The Cypress CY7C4241V-15JXCT is a synchronous FIFO in the CY7C series, organized 4K words deep by 9 bits wide (36K total). It clocks at 66.7 MHz, with 11 ns access time.
36K (4K x 9) — sizing the buffer for your backpressure latency
The 4K x 9 organization means 4096 storage locations, each holding 9 bits — the ninth bit is often used as a parity or control flag alongside the 8-bit data byte. The depth determines how long the FIFO can absorb incoming data while the downstream device is busy or the bus is stalled. If your system's worst-case backpressure latency exceeds the time it takes to fill 4096 words at 66.7 MHz (about 61 µs), you will overflow the FIFO and lose data. The programmable flags let you set almost-full and almost-empty thresholds so the controller can throttle before overflow or underflow occurs.
This part carries an official lifecycle status of Obsolete. The last-time-buy window from Cypress (now Infineon) has closed; no new factory orders are accepted. If you have an active BOM line using this FIFO, the immediate action is to qualify a pin-compatible replacement — Cypress's own synchronous FIFO family includes parts with the same 32-PLCC footprint and 3.3 V supply, though the exact density and speed grade must be verified against your timing budget.
32-PLCC J-Lead — footprint and rework
The package is a 32-lead PLCC with J-bend leads, body size 11.43 x 13.97 mm. It is a surface-mount package but with the leads tucked under the body, so visual inspection of solder joints requires an angled view or X-ray.
This restricts the part to indoor, temperature-controlled environments — office equipment, lab instruments, telecom central-office racks, and consumer electronics. It is not rated for industrial floor, automotive under-hood, or outdoor telecom cabinets where the ambient can drop below freezing or exceed 70°C.