A winner-take-all circuit for judging a channel receiving an analog signal having the largest or smallest value among multiple channels upon input of analog signals. Each basic circuit includes a detecting unit for comparing an input voltage with a reference voltage, and a feedback current generating unit for outputting a feedback current that determines a judging range in response to an output voltage from the detecting unit. The winner-take-all circuit also includes a tenth transistor serving as a common transistor to all the basic circuits. The tenth transistor secures, even when an input voltage is small, a current that should flow through a sixth transistor serially connected to the seventh transistor that determines an amount of a feedback current from the feedback current generating circuit. As a result, even when there are fewer k channels receiving input voltages having the highest level and slightly lower ones compared with all the n channels, a feedback current is secured in a sufficient amount to vary the reference voltage. In addition, the winner-take-all circuit of the present invention comprises analog circuits, thereby making the structure simpler compared with a counterpart that processes digital data. IMAGE
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