An 833-MHz 1.5-W 18-Mb CMOS SRAM with 1.67 Gb/s/pin

This paper describes an 833-MHz 18-Mb CMOS SRAM with a 1.67-Gb/s/pin data rate. Issues that had to be overcome from previous-generation SRAMs to meet the performance goals are addressed. The SRAM has been successfully fabricated using a 0.18-/spl mu/m CMOS process with copper interconnects. It operates in two user-selectable double-data-rate modes (DDR and DDR2) and consumes 1.5 W of power at 833 MHz. In addition to the performance benefits resulting from this 0.18-/spl mu/m copper technology, architecture improvements, a data-to-echo-clock tracking system, and data symmetric output drivers made possible the high frequency of operation.