Current-mode analog fuzzy hardware with voltage input interface and normalization locked loop

A voltage-input current-output membership function circuit (MFC) and a normalization locked loop (NLL) are proposed. They are useful building blocks for current-mode analog fuzzy hardware. The voltage-input current-output MFC consists of two-source-coupled-type operational transconductance amplifiers (OTAs). The MFC is used in the input parts of the analog fuzzy hardware system. The fuzzy hardware system can execute the singleton fuzzy control algorithm. In the algorithm, the weighted average operation is processed. When the weighted average operation is directly realized by analog circuits, a divider must be implemented. The NLL circuit, which can process the weighted average operation without the divider, is implemented using a one-source-coupled OTA. The proposed circuits were designed by using 2-μm CMOS design rules and their operations were confirmed using SPICE simulations