Optimizing with phases: design and application space assessment for networks of phase-locked Ring Oscillators

We investigate the operating conditions under which networks of coupled phase-locked Ring Oscillators can successfully map to Ising models in order to efficiently solve optimum search problems, shedding light on the fundamental design space trade-offs impacting solution quality. We designed and experimentally measured a test chip in 22nm FD-SOI technology with built-in readout. By solving various fully-connected 5-node graphs encoding 3-level Weighted MAX-CUT problems, we discuss the challenges associated to balancing the relative strength of coupling and synchronization signals.