Patent ID: 7155175

Claim:
A radio transceiver of a telecommunication system, the radio transceiver including an integrated circuit comprising a phase locked loop, the phase locked loop comprising: a voltage controlled oscillator for generating an output signal with a frequency proportional to a control voltage fed into the voltage controlled oscillator; a detector unit operationally connected to the voltage controlled oscillator for forming waveforms, based on a reference signal and a feedback signal, the feedback signal being proportional to the output signal of the voltage controlled oscillator; a loop filter for forming the control voltage for the voltage controlled oscillator; a charge source for providing charge for the loop filter during an active state of the charge source, based on a waveform generated by the detector unit; a charge sink for removing charge from the loop filter during the active state of the charge sink, based on a waveform generated by the detector unit; a source switch for conducting at least a portion of parasitic charge of the charge source to the ground between two successive active states of the charge source; and a sink switch for conducting at least a portion of parasitic charge of the charge sink to the ground between two successive active states of the charge sink.