Memory density and speed grade
The CY7C1381D-100BZIT is a 18 Mbit synchronous SRAM organized as 512K words by 36 bits. The 100 MHz clock rate and 8.5 ns access time place it in the mid-range speed bin for this density — suitable for cache, buffer, or look-up table applications where the bus clock runs at or below 100 MHz and the 8.5 ns window covers the address-to-data latency.
Temperature grade and supply voltage
The supply range is 3.135 V to 3.6 V — a 3.3 V nominal rail with ±5 % tolerance keeps the part inside its operating window; a 3.0 V rail would drop below the minimum at the low end.
The 165-FBGA footprint requires a multi-layer PCB with via-in-pad or microvia fan-out for the inner rows.
Infineon (formerly Cypress) has marked the CY7C1381D-100BZIT as obsolete. For a BOM that already carries this part, the supply posture is quoted-to-order; for a new design, a pin-compatible alternative from the same or a competing family should be evaluated.