Cool-CIM: Cryogenic Operation of Analog Compute-In-Memory for Improved Power-efficiency

Analog computing-in-memory (ACIM) is a promising technology that performs computation on the bitlines to alleviate memory bottleneck, but the power consumption of peripheral circuits limits its power efficiency (TOPS/Watt). This work shows that a cryogenically cooled ACIM (Cool-CIM) can leverage improved device characteristics, such as higher ION/IOFF ratio, and higher transconductance, to lower the operating voltage and power of peripheral circuits. Circuit simulations with empirically calibrated models of 14nm FinFET at cryogenic temperature show 54% reduction in EDP and 80% increase in TOPS/W for voltage optimized cryogenic ACIM compared to 300K operation. The study establishes the feasibility of in-sensor processing of analog signals in cryogenic infrared sensors.