Patent ID: 8242825

Claim:
An integrated control circuit, comprising: a capacitor coupled to develop a first voltage during a first time duration in response to a charge current received by the capacitor and to develop a second voltage during a second time duration in response to a discharge current provided by the capacitor and wherein the charge current is generated in response to a control signal; a comparator coupled to the capacitor to generate an output indicating when the capacitor reaches the second voltage; a control logic that is coupled to output a periodic output signal, wherein the control logic sets a duty ratio of the periodic output signal in response to a time that it takes the capacitor to discharge from the first voltage to the second voltage; and an oscillator coupled to provide a timing signal to the control logic, wherein a period of the periodic output signal is a period of the timing signal, and wherein the control logic includes an output that is coupled to the oscillator to change a frequency of the oscillator.