Fixed-ratio adaptive thresholding using CMOS circuits

Abstract

A CMOS chip that thresholds an array of analogue inputs and produces a fixed-ratio, corresponding array of binary outputs has been designed and tested. By adapting the threshold level, the circuit maintains a desired, selectable ratio of high-value to low-value outputs. This technique allows the primitive evaluation of quality in a sensory image that is easily adjustable for different thresholding ratios and is resilient to global offsets in the sensing environment.