256Kbit asynchronous SRAM — 15 ns, 3.3 V, 28-TSOP I
The Infineon (ex-Cypress) CY7C1399BN-15ZXI is a 256Kbit asynchronous SRAM organized as 32K x 8, with a 15 ns access time and a 3V to 3.6V supply. It uses a parallel interface and comes in a 28-TSOP I package. Rated for -40°C to 85°C.
15 ns access — what it means for the bus
The 15 ns access time sets the window from address valid to data valid. The write cycle time matches at 15 ns, so back-to-back writes at that rate are possible without wait states.
Obsolete — sourcing reality
This part is marked obsolete by Infineon. No last-time-buy window or successor is listed in the official record. For a BOM freeze or a repair line, the only channel is the independent surplus and broker market. We source and quote it to order against an RFQ; availability and current pricing are confirmed at quote time.
Package and mounting
Surface-mount 28-TSOP I, 0.465-inch body width, 11.80 mm. The footprint matches the JEDEC TSOP I standard; no special land pattern needed. Tray shipment — not tape-and-reel — so plan for pick-and-place feeder changeover if the line runs reels.