An inter-die variability compensation scheme for 0.42-V 486-kb FD-SOI SRAM using substrate control

We propose a novel substrate-bias control scheme for FD-SOI SRAM that suppresses inter-die variability and achieves low-voltage operation. Substrate-bias control circuits automatically detect an inter-die threshold-voltage variation, and then maximize read/write margins of memory cells. We confirmed that a 486-kb SRAM operates at 0.42 V, in which an FS/SF corners can be compensated as much as 0.14 V or more.