Patent ID: 8981855
Filing Date: 2015-03-17
Classification: H03J,H03L

Abstract:
1. An apparatus, comprising: a detector module configured to generate a first signal as a function of a second signal, the second signal being generated based on a plurality of capacitor units, the first signal being used to control a first capacitor unit of the plurality of capacitor units to stabilize a frequency of the second signal; and a ramp module configured to generate a third signal based on a fourth signal, generate the fourth signal by counting with a counter in response to a fifth signal generated when the first signal is out of the predetermined range, generate a plurality of control signals, and select either the third signal or one of the control signals as a voltage control signal that is used to control a second capacitor unit of the plurality of capacitor units to change a capacitance of the second capacitor unit to keep the first signal in the predetermined range.