Patent ID: 8692608

Claim:
A charge pump system comprising: a charge pump comprising an output end for providing an output voltage; a ring oscillator comprising an output end coupled to a control end of the charge pump for providing an oscillation output to the charge pump; a comparing circuit comprising: a first impedance having a first end coupled to the output end of the charge pump; a second impedance having a first end coupled to a second end of the first impedance, and a second end coupled to ground; and a comparator comprising: a first input end coupled to the second end of the first impedance; a second input end for receiving a reference voltage; and an output end; and a discharge circuit comprising: a first switch having a first end directly coupled to the output end of the charge pump, and a control end coupled to the output end of the comparator; a second switch having a first end coupled to a second end of the first switch, and a second end coupled to the ground; and a third impedance having a first end coupled to the output end of the charge pump, and a second end coupled to a control end of the second switch.