Integrated circuit with ring oscillator

An integrated circuit comprising:

• a ring oscillator configured to include one or more delay cells having a delay value and to generate two or more periodic waves;
• and
• a phase controller configured to change the delay value of the delay cells from a first delay value to a second delay value during a first period, and then to restore the changed delay value to the first delay value, thereby shifting phases of the periodic waves,
• wherein the phase controller changes the delay value of the delay cells from the first delay value to the second delay value in response to a phase comparison result of one periodic wave among the periodic waves and a reference wave, and changes the delay value of the delay cells from the second delay value to the first delay value in response to a phase comparison result of another periodic wave among the periodic waves and the reference wave.

An integrated circuit comprising:

• a ring oscillator configured to include one or more delay cells having a delay value and to generate two or more periodic waves;
• and
• a phase controller configured to change an operation current of the delay cells from a first current amount to a second current amount, during a first period, and then to restore the changed operation current to the first current amount,
• wherein each of the delay cells comprises:
• a delay unit configured to delay an input signal by the delay value thereof;
• a first current source configured to control the amount of a first current based on a main control voltage;
• a second current source configured to control the amount of a second current based on a first sub control voltage;
• and
• a third current source configured to control the amount of a third current based on a second sub control voltage,
• wherein the phase controller decreases the level of the first sub control voltage by an amount corresponding to a difference between the first and second current amounts, during the first period, and then increases the level of the second sub control voltage by an amount corresponding to the difference between the first and second current amounts.