15 ns access, 256 Kbit, 5V-only — what fits
The CY7C199C-15VXI is a 256 Kbit asynchronous SRAM organized as 32K x 8 bits with a 15 ns access time — the 15 ns ceiling means the memory can complete a read or write cycle in 15 ns, which sets the bus timing margin for the host controller. The 4.5V–5.5V supply range confirms this is a 5V-only part; it does not operate at 3.3V.
Obsolete — no official successor on record
No pin-compatible successor has been assigned by the manufacturer — the base product number CY7C199 family has no direct replacement in the current Infineon SRAM portfolio. For existing BOM lines, the procurement path is through independent surplus and authorized-distributor excess inventory. A board redesign to a 3.3V asynchronous SRAM (e.g., a 256Kbit x 8 in TSOP or BGA) is the typical migration path for new builds.