Image Number 4 for United States Patent #5120984.
A sawtooth generator for an oscilloscope which provides an accurate DC voltage control after flyback of the sawtooth voltage. The sawtooth generator includes a balance circuit in the control loop and an error amplifier with symmetrical outputs. A current-mirrored copy of the integration current is supplied as the tail current for the balance circuit. The control loop is thus forced to control around a zero error signal.