A CMOS Current-Mode Dynamic Programming Circuit

Dynamic programming (DP) is a fundamental algorithm for complex optimization and decision-making in many engineering and biomedical systems. However, conventional DP computation based on digital implementation of the Bellman-Ford recursive algorithm suffers from the “curse of dimensionality” and substantial iteration delays which hinder utility in real-time applications. Previously, an ordinary differential equation system was proposed that transforms the sequential DP iteration into a continuous-time parallel computational network. Here, the network is realized using a CMOS current-mode analog circuit, which provides a powerful computational platform for power-efficient, compact, and high-speed solution of the Bellman formula. Test results for the fabricated DP optimization chip demonstrate a proof of concept for this solution approach. We also propose an error compensation scheme to minimize the errors attributed to nonideal current sources and device mismatch.