Abstract: In a method of the invention for providing clock signals to a mixed signal telecommunication chip having a communication signal in a communication signal band, said clock signals comprise a central clock frequency signal and sub-frequency signals which are multiples or divisions of said central clock frequency signal. The central clock frequency signal is selected such that the central clock frequency signal and the sub-frequency signals are located outside the telecommunication signal band. The a mixed signal telecommunication chip of the invention takes advantage of the above clock planning.