A Current-Mode Hysteretic Winner-take-all Network, with Excitatory and Inhibitory Coupling

Winner-take-all (WTA) circuits are commonly used in a wide variety of applications. One of the most used current-mode WTA designs is the one originally proposed by Lazzaro et al. [1]. Several extensions to this design have been suggested in the past. In this paper we present a variant of this current-mode WTA circuit, containing all of the enhancements previously proposed, together with new additional modifications that endow it with interesting hysteretic and lateral inhibition and excitation properties. We compare the performance of this WTA circuit to the original WTA design, providing experimental data obtained from a VLSI chip containing both types of circuits, designed using closely matched layouts. We derive analytically the response properties of the circuit’s lateral diffusion network, pointing out the differences to previously proposed diffusion networks, and present experimental data confirming the theoretical predictions. We also describe application domains that can best exploit these types of hysteretic WTA circuits.