A low cost high performance register-controlled digital DLL for 1 Gbps/spl times/32 DDR SDRAM

A low cost high performance register-controlled digital delay-locked loop (DLL) that has novel resolution-enhancing structure with inherent duty cycle correction capability was developed for 1 Gbps/spl times/32 DDR SDRAM. Experimental results in a 0.13 /spl mu/m 4 M/spl times/32 DDR SDRAM show <25 ps peak-to-peak jitter with quiet supply,