Patent ID: 8618885

Claim:
An oscillator system, the system comprising: a first voltage-to-current converter configured to convert a first voltage to a first current; a second voltage-to-current converter configured to convert a second voltage to a second current; a first current-mode N-bit digital-to-analog converter configured to receive the second current, a first clock signal and a second clock signal, and to generate a third current, N being a first positive integer, the first clock signal being associated with a first clock frequency corresponding to a first clock period, the second clock signal being associated with a second clock frequency corresponding to a second clock period; and a first current comparator configured to compare the first current to the third current and to generate the second clock signal based on at least a comparison of the first current and the third current; wherein the first current comparator is configured to: provide the second clock signal at a first voltage level if the third current is smaller than the first current in magnitude; and provide the second clock signal at a second voltage level if the third current is equal to or larger than the first current in magnitude; wherein the first current-mode N-bit digital-to-analog converter is configured to: decrease the third current in magnitude to a first predetermined current level if the second clock signal changes from the first voltage level to the second voltage level; and increase the third current in magnitude if the second clock signal does not change from the first voltage level to the second voltage level.