400 MHz DDR II+ SRAM — throughput and bus fit
The CY7C1568KV18-400BZXC is a 72 Mbit synchronous SRAM organized as 4M words by 18 bits, clocked at 400 MHz using DDR II+ double-data-rate signalling. At 400 MHz the data bus toggles at 800 MT/s per pin — the 18-bit-wide interface delivers a peak bandwidth of 14.4 Gbit/s. The 1.7 V to 1.9 V single-rail supply keeps the core power plane simple; the 165-FBGA (13x15 mm) footprint is the standard package for this density grade. This is a volatile memory — data is retained only while power is applied. The DDR II+ technology means the device samples data on both clock edges, halving the required bus clock for a given throughput compared to single-data-rate SRAM.
Temperature grade and board-level integration
This covers most networking, telecom, and test-equipment chassis environments but does not extend to -40°C industrial or automotive under-hood applications. The 165-FBGA (13x15 mm) package uses a fine-pitch ball array; board assembly requires a controlled reflow profile and post-solder X-ray inspection to verify ball wetting and voiding. The 400 MHz clock rate sets a tight timing budget for the PCB trace length matching between the SRAM and the controller — the skew budget between DQ and DQS lines is typically ±50 ps for DDR II+ interfaces. The 1.7 V to 1.9 V supply rail must be regulated to within ±50 mV at the device balls to stay within the VDD tolerance window.
The tray packaging means pick-and-place lines need a tray feeder or a tube-to-tray conversion — not a standard tape-and-reel input.