Patent ID: 7944277

Claim:
A circuit comprising: an oscillator circuit; a charge pump coupled to receive an oscillating signal from said oscillator circuit, said charge pump operable to provide an output voltage; an amplifier responsive to said output voltage and a reference voltage, said amplifier operable to provide a control signal, said control signal coupled to alter a frequency of said oscillator circuit; a current mirror responsive to said output voltage of said charge pump, said current mirror operable to output a constant current and suppress noise from said output voltage; a filter arranged between said charge pump and said current mirror, said filter operable to further suppress noise from said output voltage; a voltage reference, said voltage reference comprising a first device, said voltage reference providing said reference voltage to said amplifier; and a feedback network comprising a second device, said feedback network coupled to receive said output voltage and to provide an indication of said output voltage to said amplifier, wherein said first device and said second device provide a matching voltage drop that tracks over manufacturing variations, wherein said current mirror is operable to isolate said filter from a load circuit in communication with said current mirror, and said load circuit includes a regulator loop operable to generate a consistent regulated voltage, and wherein said output voltage is responsive to said frequency of said oscillator circuit.