The Infineon CY7C1426JV18-300BZC is a 36 Mbit QDR II synchronous SRAM organized as 4M x 9 bits, clocked at 300 MHz with a parallel interface. This is a high-bandwidth memory part designed for networking line cards, telecom switch fabrics, and test equipment where back-to-back read/write throughput matters and dead cycles on the bus cost performance.
300 MHz clock — bus margin and throughput
At 300 MHz the QDR II interface delivers a 1.2 Gbps data rate per pin (double-data-rate on both read and write ports). The 4M x 9 organisation means the part handles a 9-bit-wide word; in a typical 36-bit or 72-bit memory subsystem you'll bank four or eight of these to match the data bus.
Obsolete — sourcing from the independent channel
Infineon lists the CY7C1426JV18-300BZC as Obsolete. Date-code provenance matters here: verify the parts come from a traceable lot, especially for a BGA package that cannot be visually inspected for moisture or handling damage.
165-FBGA footprint and rework considerations
The 165-ball FBGA (15x17 mm) is a fine-pitch BGA. The package is surface-mount only, and the tray shipping medium means the parts arrive in anti-static trays.