18K FIFO at 50 MHz — the access-time ceiling
The CY7C429-20JXCT is an asynchronous FIFO from the CY7C family, organized 2K words deep by 9 bits wide. It clocks at a 50 MHz data rate with a 20 ns access time — the access window determines how fast the read pointer can retrieve a word after the read-enable strobe, setting the real throughput in a burst transfer. The 9-bit width accommodates an eighth parity or control bit alongside an 8-bit byte, common in telecom or data-acquisition buffers where a sideband flag travels with the data word.
Retransmit and expansion for deep buffering
Retransmit capability lets the FIFO re-read data from a marker without a full reset — useful in retry protocols or data recovery after a transmission error. Expansion support allows depth- or width-cascading multiple devices to build a larger buffer array without external glue logic. The 55 mA maximum supply current at 5 V is typical for a 50 MHz FIFO in this density — the active current scales linearly with clock rate; a slower system clock reduces the draw proportionally.
Infineon lists the CY7C429-20JXCT as obsolete. The commercial temperature grade (0°C to 70°C,) restricts the part to indoor or controlled environments — not rated for industrial or automotive ambient.
Supply rail and board integration
The J-lead PLCC footprint is surface-mount but requires a socket or reflow profile compatible with the 32-lead body (11.43 x 13.97 mm). No programmable flags or FWFT (First-Word Fall-Through) support — the empty/full flag timing is fixed. For designs that need programmable almost-empty or almost-full thresholds, a different FIFO variant is required.