Patent ID: 7403049

Claim:
A triangular wave generation circuit, comprising: a first capacitor in which potential of a first terminal is fixed; a first constant-current source which supplies current to a second terminal of said first capacitor; a second capacitor in which potential of a first terminal is fixed; a second constant-current source which supplies current to a second terminal of said second capacitor; a first switch provided between the second terminal of said first capacitor and the second terminal of said second capacitor; a second switch provided on a current path of said second constant-current source; a third constant-current source which draws current from said first capacitor and said second capacitor; and a switch controller which turns on said first switch and turns off said second switch when an output voltage appearing in the second terminal of said first capacitor reaches a predetermined upper-limit voltage and which turns off said first switch and turns on said second switch when the output voltage drops to a predetermined lower-limit voltage.