Auto-Scaling Overdrive Method Using Adaptive Charge Amplification for PRAM Write Performance Enhancement

作者：Choi Sukhwan^*; Kim Hyun Sik; Jung Seungchul; Sung Si Duk; Yuk Young Sub; Yim Hyuck Sang; Shin Yoonjae; Cheon Jun Ho; Ahn Changyong; Kim Taekseung; Kim Yongki Brave; Cho Gyu Hyeong

来源：IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS, 2014, 61(11): 3165-3174.

DOI：10.1109/TCSI.2014.2334813

• Multi-level cell (MLC)
• overdrive
• phase change random access memory (PRAM)
• phase-change memory
• program-and-verify (PNV)
• write driver

A PRAM write driver with an auto-scaling overdrive method is presented. The proposed overdrive method significantly reduces the rise time of the cell-current pulse for bit-line parasitic components of 3 pF and 6 k Omega, and it lowers the complexity of the overdrive control using an adaptive charge amplification technique. A rise time of less than 15 ns is achieved and shortened up to 4.7 times, and the total write-throughput is increased. The rise time is reduced consistently for all levels of the target-current by the auto-scaling effect. Therefore, cell heating control becomes more linear in program-and-verify (PNV) operation. Due to its simple adding-on structure, it is easily compatible with a conventional write driver. A prototype chip was implemented using a 0.18-mu m CMOS process. It is also applicable to smaller-scale technology.

• 出版日期2014-11