CMOS fuzzifier using mixed-signal techniques with emphasis in power consumption

A novel mixed-signal CMOS membership function generator (MFG) is presented. It is based on an enhanced version of a linear tunable transconductor proposed in [1] and implements trapezoidal/triangular functions with all parameters (slope, position, width and height) independently and continuously adjustable. It is suitable to be used in analog and mixed-signal fuzzy circuits working in current mode. The computer simulations that verify the characteristics and performances of this circuit are given, showing high speed operation (up to 10 MHz input signals, working in continuous time) with low power consumption (about 80 µA per MFG). The MIN-MAX rule of composition has been selected for the inference process. An innovative method for limiting power consumption has been devised for this kind of MFG. To this purpose, the winner-take-all circuit that makes the MIN operator periodically deactivates its non-winning inputs. For non-fast varying input signals, considerable power saving can be achieved.