Current-mode fully-programmable piece-wise-linear block for neuro-fuzzy applications

A new method to implement an arbitrary piece-wise-linear characteristic in current mode is presented. Each of the breaking points and each slope is separately controllable. As an example a block that implements an N-shaped piece-wise-linearity has been designed. The N-shaped block operates in the subthreshold region and uses only ten transistors. These characteristics make it especially suitable for large arrays of neuro-fuzzy systems where the number of transistors and power consumption per cell is an important concern. A prototype of this block has been fabricated in a 0.35 μm CMOS technology. The functionality and programmability of this circuit has been verified through experimental results