Patent ID: 7019471

Claim:
An integrated circuit for providing an oscillating signal in accordance with the charging and discharging of a capacitor, comprising: comparator circuitry for comparing the voltage across the capacitor to a reference voltage and generating a charge/discharge signal in response to the value of the voltage across the capacitor as compared to the reference voltage, wherein the reference voltage is switched between at least two values comprising a first reference voltage and a second reference voltage, and wherein the charge/discharge signal has a first binary value when the voltage across the capacitor exceeds the first reference voltage and a second binary value when the reference voltage is below the second reference voltage; one of the first and second binary values causing charging of the capacitor and the other causing discharging of the capacitor; and switch circuitry for switching the reference voltage to the first reference voltage when the charge/discharge signal goes from the first value to the second value and to the second reference voltage when the charge/discharge signal goes from the second value to the first value.