Patent ID: 7020229

Claim:
A phase-locked loop, comprising: a phase detector having an output outputting, per clock cycle, a current pulse with a pulse duration being a measure of a phase difference between an input signal and an output signal of the phase-locked loop; a loop filter connected downstream of said phase detector, said loop filter having a converter device, at least one controllable switching device connected to said converter device, and at least two switchable capacitive elements for storing said current pulse and connected to said controllable switching device, said converter device, said controllable switching device and said switchable capacitive elements able to be connected up such that said converter device provides a proportional current derived from said current pulse coupled into at least one of said switchable capacitive elements, the proportional current having an amplitude being constant over an entire length of a clock period; and an oscillator connected downstream of said loop filter, said oscillator receiving the proportional current.