PROBLEM TO BE SOLVED: To provide a vertical saw tooth wave oscillation circuit which can shorten the time required upto the time when a saw tooth wave having a fixed amplitude is obtained. ;SOLUTION: A vertical saw tooth wave oscillation circuit is provided with a first capacitor 6 which is alternately charged and discharged synchronously to a vertical synchronizing signal, an error amplifier circuit 7 which receives the output of the capacitor 6 through its noninverted input, and a current mirror circuit 5 which supplies a charging current to the capacitor 6. The oscillation circuit is also provided with a first voltage/current conversion circuit 11 which supplies the first input current of the current mirror circuit 5 upon receiving the output of the amplifier circuit 7, a coring circuit 12 which outputs a control voltage correspondingly to the difference between the output of the amplifier circuit 7 and a reference voltage VC, and a second voltage/current conversion circuit 13 which controls the charging current of the capacitor 6 with a second input current by generating the second input current upon receiving the control voltage.;COPYRIGHT: (C)2000,JPO
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