Voltage Controlled Oscillator based Ising Machine for Solving Combinatorial Optimization Problems
M. Fahmin Rahman, H M Tahmeed-Ul-Islam, Tasnim Sobhan Upoma, Orchi Hassan · 2024
CMOS-based oscillatory Ising machine (OIM) has gained significant interest as hardware accelerators for solving combinatorial optimization problems (COP) due to their scalability, speed, and compatibility with existing manufacturing process. In this paper, we present a voltage-controlled oscillator (VCO) based Ising solver design which can effectively solve both single-solution and multi-solution optimization problems. We have designed the VCO to achieve a $50 \%$ duty cycle, which is essential for OIM operation, and it provides frequency tunability through voltage control, allowing for better network stabilization. Our proposed design can address a wide range of practical problems, which we demonstrate by successfully solving four distinct types of COPs.