Method and circuit for generating triangular waveforms opposite in phase

Abstract

A circuit and a method generate first and second triangular waveforms opposite in phase to each other. The circuit includes a capacitor having a first plate coupled to a first output at which the first triangular waveform is produced and a second plate coupled to a second output at which the second triangular waveform is produced. First and second switches are coupled between a first voltage reference and the first and second plates, respectively, of the capacitor. The circuit also includes a controller having a first output coupled to the control terminal of the first switch and a second output coupled to a controlled terminal of a second switch. The controller is structured to produce at the first and second outputs respective first and second control signals in opposition to each other and thereby control the first and second switches in opposition to each other. The circuit may include a differential stage having first and second inputs and an output with the first input being coupled to a second voltage reference and the output being coupled to the capacitor. A first resistor may be coupled between the first output of the circuit and the second input of the differential stage and a second resistor may be coupled between the second output of the circuit and the second input of the differential stage. Such a differential stage and resistors insure that the average value of the triangular waveforms is equal to the second voltage reference.