128K x 36 synchronous SRAM — the 100 MHz bus-fit
The CY7C1351F-100AC is a 4.5 Mbit synchronous SRAM organized as 128K words of 36 bits each. The 36-bit word width accommodates 32 data bits plus four parity or ECC bits in a single chip, which simplifies memory controller design for networking and telecom equipment that needs byte-level parity coverage. The 100 MHz clock frequency and 8 ns access time define the bus timing margin: at 100 MHz the cycle time is 10 ns, so the 8 ns access gives a 2 ns window for address-to-data setup before the next rising edge — tight but workable with controlled PCB impedance and matched trace lengths. The single-data-rate (SDR) interface latches addresses on the rising edge only, which halves the pin count versus DDR but limits peak bandwidth to 100 MT/s per chip.
If your system sees extended temperature swings or requires AEC-Q100 qualification, this is not the fit.
Package — 100-TQFP, 14x20 mm body
The Tray shipping medium is the factory packaging for this order code. The 100-pin QFP is a common footprint for synchronous SRAMs in this density class, which opens the door to pin-compatible second sourcing — but the obsolete status means any alternate must be qualified independently.