New low-voltage fully programmable CMOS triangular/trapezoidal function generator circuit

A versatile lowwvoltage CMOS circuit with a triangular/trapezoidal transconductance characteristic and independently programmable slope (keeping constant height or constant width), height (keeping constant slope or constant width), and horizontal position is presented. Simulation results using Cadence DFW-II that verify the functionality of the circuit with +/- 1.5-V supplies are presented. A chip prototype has been fabricated in a 0.5-mu m technology and experimentally verified. The circuit can find application in the implementation of high resolution, high speed folding analog-to-digital converters, in piecewise-linear approximation, and in the implementation of membership functions in analog and mixed-signal neuro-fuzzy systems.