Circuit for measuring flicker noise and method of using the same

A method of determining flicker noise, the method comprising:

• measuring a first phase noise using a first flicker noise measurement circuit, wherein the first flicker noise measurement circuit has a first number of stages and a first slope rise/fall ratio;
• measuring a second phase noise using a second flicker noise measurement circuit, wherein the second flicker noise measurement circuit has a second number of stages and a second slope rise/fall ratio;
• setting the second slope rise/fall ratio to be different from the first slope rise/fall ratio by applying a first driving force to the first flicker noise measurement circuit and a second driving force to the second flicker noise measurement circuit, wherein the second driving force is different from the first driving force;
• determining the first slope rise/fall ratio;
• determining the second slope rise/fall ratio;
• calculating a first flicker noise based on the measured first phase noise, the first number of stages and the determined first slope rise/fall ratio;
• calculating a second flicker noise based on the measured second phase noise, the second number of stages and the determined second slope rise/fall ratio;
• and
• selecting the flicker noise from a pool of flicker noise results including the first flicker noise and the second flicker noise.