72 Mbit DDR II+ SRAM with 333 MHz clock — what the specs mean for your design
The CY7C1518KV18-333BZXI is a 72 Mbit synchronous DDR II+ SRAM from Cypress, organized as 4M x 18 and clocked at 333 MHz. The x18 data width is a deliberate choice for designs that carry a parity or ECC bit per byte without widening the bus to x36 — common in networking line cards and high-end storage controllers where data integrity matters but board area is tight. The 333 MHz clock yields a peak data rate of 667 MT/s per pin pair (double data rate), which keeps up with high-throughput ASICs and FPGAs that run a 166–200 MHz controller clock. Supply range of 1.7V to 1.9V means it runs cleanly off a nominal 1.8V rail; the 200 mV tolerance matters when the regulator has ripple or load transients.
Do not assume a direct drop-in without verifying the timing and loading against your controller.
Package and board-level considerations
Supplied in a 165-ball LBGA (13x15 mm body), surface-mount only. The fine-pitch BGA calls for controlled solder-paste volume and X-ray inspection post-reflow. The 1.7V–1.9V core supply needs a dedicated rail with adequate decoupling; place at least one 100 nF capacitor per four balls near the center of the array.