Low ${\rm VDD\min}$ Swing-Sample-and-Couple Sense Amplifier and Energy-Efficient Self-Boost-Write-Termination Scheme for Embedded ReRAM Macros Against Resistance and Switch-

The designs of resistive RAM (ReRAM) macros are limited by 1) a small sensing margin, limited read- VDDmin, and slow read access time (T_AC) caused by a high cell-resistance and small cell-resistance-ratio (R-ratio) and 2) poor power integrity and increased energy waste attributable to a large SET dc-current (I_DC-SET) resulting from the wide distribution of write (SET)-times (T_SET). This study proposes a swing-sample-and-couple (SSC) voltage-mode sense amplifier (VSA) to enable an approximately 1.8+x greater sensing margin for lower VDD min and a 1.7+x faster read speed across a wide VDD range, compared with conventional VSAs. A 4T self-boost-write-termination (SBWT) scheme is proposed to cut off the I_DC-SET of devices with a rapid T SET. The SBWT scheme reduces 99+% of the I_DC-SET with an area penalty below 0.5%. A fabricated 512 row 28 nm 1 Mb ReRAM macro achieved T_AC = 404 ns when VDD=0.27 V and confirmed the I_DC-SET cutoff by the SBWT.