  Physical Ising machines rely on nature to guide a dynamical system towards an
optimal state which can be read out as a heuristical solution to a
combinatorial optimization problem. Such designs that use nature as a computing
mechanism can lead to higher performance and/or lower operation costs and hence
have attracted research and prototyping efforts from industry and academia.
Quantum annealers are a prominent example of such efforts. However, some
physics-centric Ising machines require stringent operating conditions that
result in significant bulk and energy budget. Such disadvantages may be
acceptable if these designs provide some significant intrinsic advantages at a
much larger scale in the future, which remains to be seen. But for now,
integrated electronic designs of Ising machines allow more immediate
applications. We propose one such design that uses bistable nodes, coupled with
programmable and variable strengths. The design is fully CMOS compatible for
chip-scale applications and demonstrates competitive solution quality and
significantly superior execution time and energy.
