Infineon has classified the CY7C25682KV18-400BZXC as Last Buy — the manufacturer is winding down production, and this is the final procurement opportunity before the part becomes unavailable through authorized channels. For a BOM that already carries this 72 Mbit DDR II+ SRAM, the decision is straightforward: secure the lifetime buy quantity now, or plan a board respin to a replacement memory device before the last-time-buy deadline passes.
400 MHz DDR II+ — the bandwidth story
At 400 MHz clock, this synchronous SRAM delivers double-data-rate transfers on every clock edge — the 4M x 18 organization means each access moves 18 bits per cycle, so the peak bandwidth is 400 MHz × 2 edges × 18 bits = 14.4 Gbit/s, or 1.8 GB/s. That bandwidth targets network switch buffers, telecom line cards, and high-end test equipment where the SRAM must keep pace with a 400 MHz ASIC or FPGA memory controller without wait states.
Package and supply — board-fit constraints
Commercial temperature grade (0°C to 70°C) limits this part to controlled indoor environments — a telecom cabinet with ambient above 55°C needs thermal simulation to confirm the junction stays within the 70°C ceiling.