High speed and high resolution current winner-take-all circuit in conjunction with adaptive thresholding

A CMOS high performance current mode winner-take-all (WTA) circuit is presented. The circuit employs a novel technique for inhibitory and excitatory feedbacks based on input currents average computation, achieving both high speed and high resolution. The proposed WTA circuit can be used in a wide variety of applications, while its architecture allows implementation of adaptive thresholding, making it also suitable for visual attention and tracking applications, where "background" inhibition and false alarm reduction are required. The circuit is designed for operation with a wide range of input current values, allowing its integration with circuits operating both in subthreshold and strong inversion regions. Two circuits, each for a different range of input currents, have been implemented in a standard 0.35 μm CMOS process available through MOSIS and are operated via a 3.3 V supply. Their operation is discussed and simulation results are reported.