Mixed-signal AI accelerators offer the possibility of higher energy efficiency for moderate resolution computations compared to their digital counterparts. All-analog implementations, where all operations are performed in the analog domain, can further improve this energy advantage. An energy efficient multiply-accumulate cell for all-analog neural layer processing macros is presented. The proposed analog two-quadrant multiplier circuit consists of two complementary MOSFETs where the pulse width modulated input activation is applied to the gates and the weight signal to the isolated back-gate. The analog multi-bit resolution weight is dynamically stored on a memory capacitor. The multiply-accumulate operation result is represented by charge accumulated on a summation line and drawn from or put onto a computation capacitance. Simulation results based on a 22 nm FD-SOI CMOS technology show that the cell consumes about 0.67 fJ for a circuit-level multiply-accumulate operation. An area efficiency of 166 × 10 12 MAC/s/mm 2 is achieved.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.