Frequency-locked clock generator

Abstract

A frequency-locked clock generator includes a voltage-controlled oscillator (VCO), a frequency-to-current converter, a reference current source and a gain stage. The VCO generates an output signal. The frequency-to-current converter generates a converter current proportional to a frequency of the output signal. The reference current source generates a reference current. The gain stage generates a control signal based on a difference between the converter current and the reference current. The control signal is applied to the VCO to adjust the frequency of the output signal. Feedback forces the VCO to generate an output clock signal such that the corresponding current it produces (i.e., the converter current) is equal to the reference current. When in lock, the frequency of the output signal is determined by a time constant (or equivalent time constant) of the frequency-locked clock generator.

Dependencies are inferred from the claim text.