Title :
An 8.1-ns Column-Access 1.6-Gb/s/pin DDR3 SDRAM With an 8:4 Multiplexed Data-Transfer Scheme
Author :
Fujisawa, Hiroki ; Kubouchi, Shuichi ; Kuroki, Koji ; Nishioka, Naohisa ; Riho, Yoshiro ; Noda, Hiromasa ; Fujii, Isamu ; Yoko, Hideyuki ; Takishita, Ryuuji ; Ito, Takahiro ; Tanaka, Hitoshi ; Nakamura, Masayuki
Author_Institution :
ELPIDA Memory Inc, Kanagawa
Abstract :
Three circuit techniques for an 8.1-ns column-access 1.6-Gb/s/pin 512-Mb DDR3 SDRAM using 90-nm dual-gate CMOS technology were developed. First, an 8:4 multiplexed data-transfer scheme, which operates in a quasi-4-bit prefetch mode, achieves a 3.17-ns reduction in column-access time, i.e., from 11.3 to 8.13 ns. Second, a dual-clock latency counter reduces standby power by 22% and cycle time from 1.7 to 1.2 ns. Third, a multiple-ODT-merged output buffer enables selection of five effective-resistance values Rtt (20, 30, 40, 60, and 120 Omega) without increasing I/O capacitance. Based on these techniques, 1.6-Gb/s/pin operation with a 1.36-V power supply and a column latency of 7 was accomplished
Keywords :
CMOS integrated circuits; DRAM chips; SRAM chips; buffer circuits; clocks; 1.2 ns; 1.36 V; 1.6 Gbits/s; 120 ohm; 20 ohm; 30 ohm; 40 ohm; 60 ohm; 8.13 ns; 90 nm; DDR3 SDRAM; ZQ calibration; data-transfer scheme; dual-clock latency counter; dual-gate CMOS technology; CMOS technology; Counting circuits; Delay; Frequency; Indium tin oxide; Operational amplifiers; Prefetching; Random access memory; SDRAM; Voltage; CMOS; DDR3; DRAM; SDRAM; ZQ calibration; data transfer; double data rate (DDR); dual clock; latency counter; output buffer;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2006.888298
