5V async SRAM for legacy bus interfaces
The Infineon CY7C1021B-15VXCT is a 1 Mbit asynchronous SRAM organized as 64K words by 16 bits. In a 5 V system the address-to-data valid window is tight; the 15 ns figure is the spec that determines whether the bus timing budget closes. Packaged in a 44-pin SOJ (Small Outline J-lead) with a 0.400-inch body width, this surface-mount footprint was common on late-1990s through mid-2000s embedded boards. The Tape & Reel delivery format suits automated pick-and-place assembly.
Infineon lists the CY7C1021B-15VXCT as Obsolete. For production BOM lines that still require this exact order code, procurement must go through the surplus and broker channel. Because no pin-compatible second source or direct replacement is documented in the available records, any substitution attempt requires a full qualification cycle — footprint match, timing verification at 15 ns, and 5 V supply compatibility. A drop-in from a different SRAM family (e.g., a 3.3 V part or a different package) will not work without board revision.