A 22-nm 32-Mb Embedded STT-MRAM Macro Achieving 5.9-ns Random Read Access and 7.4-MB/s Write Throughput at up to 150 °C

This article presents a high-precision sense amplifier technique, a fast write scheme, and a one-time-programmable (OTP) memory cell read technique applied to a 22-nm 32-Mb embedded STT-MRAM (eMRAM) macro for high-end microcontroller units (MCUs). A boosted cross-coupled sense amplifier (BCC-SA) achieves 5.1- and 5.9-ns random read access at 125 °C and 150 °C, respectively. A variable parallel bit write (VPBW) with a fast voltage setup (VPBW-FVS) scheme and write voltage always on (WVAO) mode enable 7.4-MB/s write throughput and 73% write energy reduction. A stabilization of operating conditions with variable current (SOC-VC) technique allows a sense amplifier to be shared with both embedded magnetoresistive random access memory (MRAM)-based OTP and MRAM cell read modes.