NEC ships QDR II, DDR II SRAMs for high-speed systems

NEC Corp. has shipped its QDR II and DDR II family of SRAM products for use in network switches and routers in high-speed networks such as OC-192 and OC-768.

"Emerging network standards like OC-192 and OC-768 are becoming increasingly popular in the network switch and router markets, and the data rates required to support these standards are beyond the limits of conventional SRAM technologies," said Hiroyuki Goto, senior manager for

memory engineering and marketing, NEC Electronics Inc.

The initial QDR II and DDR II products are initially available in an 18Mb configuration with I/Os that support a burst length of two or four. The QDR II SRAM devices use the QDR II-standard 165-pin, 13-by-15mm FBGA packaging that provides shorter bus lengths for minimized delays, skews, and EMI.

Both products operate from a 1.8V power source to accommodate the power specifications of high-end routers and switches. The devices also provide a data valid window of 65 percent of the clock cycle or a 1.3ns data valid window at 250MHz.

Defined by the QDR Co-Development Team, the QDR II and DDR II specifications enable system designers to maximize bandwidth in data-intensive communication applications by allowing operation speeds of up to 333MHz. The QDR II architecture features two data ports (I/O) operating twice per clock cycle to deliver a total of four data instructions per cycle.

Single I/O DDR II devices allow DDR transfers over the I/O data bus and are suitable for data-streaming operations.

The 18Mb QDR II and DDR II SRAM products are available now with a sample price of $80.