15 ns asynchronous SRAM for legacy bus timing
The Infineon CY7C1399BN-15VXIT is a 256Kbit asynchronous SRAM organized as 32K x 8, with a 15 ns access time that sets the bus-cycle window for the host controller. This speed grade suits processors and ASICs with read-cycle requirements in the 15 ns to 20 ns range — common in industrial control boards, telecom line cards, and test equipment from the late-1990s through mid-2000s design cycles.
Industrial temperature grade and deployment context
The 28-SOJ package (JEDEC MO-061, 300-mil body width) is a surface-mount outline that was widely used in high-density memory arrays on multi-layer FR4 boards. Reflow profiles follow standard J-STD-020 for MSL 3 devices; the SOJ lead form is less tolerant of board flex than a TSOP, so mechanical stress around the solder joints should be reviewed during PCB layout.
Infineon (formerly Cypress Semiconductor) has discontinued this part; no last-time-buy window remains open through the factory. Sourcing is limited to independent distribution and surplus inventory channels. Buyers should verify date code freshness and request counterfeit-screening documentation for any lot offered.