Minimising Contrastive Divergence with Dynamic Current Mirrors

Implementing probabilistic models in Very-Large-Scale-Integration (VLSI) has been attractive to implantable biomedical devices for improving sensor fusion. However, hardware non-idealities can introduce training errors, hindering optimal modelling through on-chip adaptation. This paper investigates the feasibility of using the dynamic current mirrors to implement a simple and precise training circuit. The precision required for training the Continuous Restricted Boltzmann Machine (CRBM) is first identified. A training circuit based on accumulators formed by dynamic current mirrors is then proposed. By measuring the accumulators in VLSI, the feasibility of training the CRBM on chip according to its minimizing-contrastive-divergence rule is concluded.