A 1.2 Gb/s/pin double data rate SDRAM with on-die-termination

Abstract

For operating frequencies exceeding 500 MHz, the timing margin of the I/O interface is critical and requires the data input-output timing accuracy to be within 200 ps. To meet the requirement, the designed SDRAM adopts a digitally self-calibrated on-die-termination with linearity error of /spl plusmn/1% and achieves over 1.2 Gbps/pin stable operation by using window matching and latency control. The chip is fabricated in a 0.13 /spl mu/m triple-well DRAM process.