A Single-Reference Parasitic-Matching Sensing Circuit for 3-D Cross Point PCM

3-D cross point phase change memory (PCM) is considered to be a leading 3-D technology for emerging nonvolatile memories. Besides planar parasitic elements, vertical parasitic elements will also delay the read operation in 3-D PCM. This brief concludes the five factors that affect the read operation in 3-D cross point PCM for the first time. A single-reference parasitic-matching sensing circuit is therefore proposed to speed up the read operation. Simulated in a 40-nm CMOS process, the sensing time of 64-Mbit 3-D cross point PCM is 39.67 ns compared to the conventional 185.3 ns. Monte Carlo simulations show an 84.5 ns worst sensing time compared to the conventional 364.5 ns.