A method of minimizing phase noise is provided. In operation, a first phase noise in a first circuit located on an integrated circuit is determined. Additionally, a second phase noise in a second circuit coupled to the first circuit but which is not located in the integrated circuit is determined, the second circuit being programmable. Further, the first phase noise is compared with the second phase noise. If the phase noises are about the same, it is determined that the noise source is from an algorithm of a random number generator, the second circuit is modified to optimize the performances of the integrated circuit, and the modified second circuit is copied to the first circuit. If the phase noises are different, it is determined that a source of the phase noise is at least one of a power supply coupling and a substrate coupling in the integrated circuit.