Patent ID: 7772895
Filing Date: 2010-08-10
Classification: H03L

Abstract:
1. A signal generating circuit, comprising: a detecting circuit, for generating a detecting signal according to a reference signal and an oscillating signal; a charge pump, coupled to the detecting circuit, for outputting a first output signal according to the detecting signal; a first level shifter, coupled to the charge pump, for generating a second output signal according to a voltage level of the first output signal, wherein a voltage level of the second output signal is different from the voltage level of the first output signal; a filtering circuit, coupled to the first level shifter, for generating a first filtered control signal according to the second output signal; a second level shifter, coupled to the filtering circuit, for generating a second filtered control signal according to a voltage level of the first filtered control signal, wherein a voltage level of the second filtered control signal is different from the voltage level of the first output signal; and a controllable oscillator, coupled to the second level shifter, for generating the oscillating signal according to the second filtered control signal.