Patent ID: 7348812

Claim:
A multiphased triangular wave oscillating circuit, comprising: a plurality of triangular wave generating circuits that respectively, selectively generate the output voltage of an up-slope waveform and the output voltage of a down-slope waveform; a middle point potential detecting circuit that detects a middle point potential corresponding to an average value of the output voltages of the plurality of triangular wave generating circuits; a first control circuit that controls at least one of the output voltages of the plurality of triangular wave generating circuits, so that the middle point potential detected by the middle point potential detecting circuit can be matched with a first reference voltage at a fixed level; and a second control circuit that monitors each output voltage of the plurality of triangular wave generating circuits, and switches the output voltage generation mode of the respective triangular wave generating circuit from an up-slope waveform mode to a down-slope waveform mode, or from a down-slope waveform mode to an up-slope waveform mode, when its respective output voltage reaches a reference wave crest value; wherein each triangular wave generating circuit has a respective capacitor connected between the output terminal of said triangular wave generating circuit and a second reference voltage source, a charge circuit that charges said respective capacitor to generate the output voltage of the up-slope waveform, and a discharge circuit that discharges said respective capacitor to generate the output voltage of the down-slope waveform.