JSSC 2010第4期Memory150nm CMOS

A 32-Mb SPRAM With 2T1R Memory Cell Localized Bi-Directional Write Driver and 10

一款32Mb自旋转移矩RAM芯片，采用2T1R存储单元和局部双向写入驱动器，实现高速读写。

32ns访问时间，40ns写入时间，1.8V供电

SPRAM自旋转移矩RAM2T1R存储单元双向写入驱动器隧道磁阻器件

▸创新点1：2T1R型存储单元设计（电路创新）：采用双晶体管和单电阻结构，在小尺寸单元中实现足够大的写入电流，提升存储密度和写入效率。

▸创新点2：局部双向写入驱动器（电路创新）：通过紧凑的局部化设计，有效分配写入电流，减少功耗并提高写入速度，支持双向写入操作。

▸创新点3：分离的读写层次位/源线结构（系统创新）：将读写路径分离，优化信号传输路径，减少读写干扰，提升整体系统稳定性和性能。

▸创新点4：'1'/'0'双阵列均衡参考方案（电路创新）：采用双阵列均衡参考设计，确保读取操作的稳定性，减少误读率，提高数据可靠性。

Abstract

A 32-Mb SPin-transfer torque RAM (SPRAM) chip was demonstrated with an access time of 32 ns and a cell write- time of 40 ns at a supply voltage of 1.8 V. The chip was fabricated with 150-nm CMOS and a 100 200-nm tunnel magneto-resistive (TMR) device element. A required thermal stability of 67 of the TMR device was estimated by taking into account the disturbances during read operations and data retention periods of 10 years for nonvolatile operation. The 32-Mb SPRAM chip features three cir- cuit