Triangular/square-wave generator with independently controllable frequency and amplitude

Abstract

A triangular/square-wave generator with current-controllable frequency and amplitude is presented. The generator utilizes operational transconductance amplifiers as switching elements. A prototype circuit built with commercially available components exhibits less than 2% nonlinearity in its current-to-frequency transfer characteristic from 1 to 10 Khz and -150 ppm/° C temperature coefficient of frequency over 15 ° C to 35 °C. The circuit also displays wide sweep capability and good linearity of current to amplitude. The application of the circuit to a current-controllable saw-tooth waveform generator is also presented.