Patent ID: 8373465

Claim:
An electronic device comprising a phase locked loop (PLL) including a phase frequency detector (PFD) a first charge pump (CP 1 ); a controlled oscillator (VCO), a divider (DIV), a second charge pump (CP 2 ) and control stage (DCONT); wherein an output of the phase frequency detector (PFD) is coupled to the first charge pump (CP 1 ) and an output of the first charge pump (CP 1 ) is coupled to a first control input of the controlled oscillator (VCO), the output of the phase frequency detector (PFD) is also coupled to an input of the second charge pump (CP 2 ), an output of the second charge pump (CP 2 ) is coupled to an input of the control stage (DCONT), an output of the control stage (DCONT) is coupled to a second control input of the controlled oscillator (VCO), an output of the controlled oscillator (VCO) is coupled to an input of the divider (DIV), an output of the divider is coupled to an input of the phase frequency detector (PFD), the control stage (DCONT) comprising N storage elements (S 1 , . . . ,SN) each having an output coupled to the output of the control stage (DCONT), the N storage elements being coupled in a chain such that each storage element (Si) except the first (S 1 ) and the last storage element (SN) in the chain is coupled to a preceding storage element (Si−K 1 ) and a subsequent storage element (Si+K 2 ), and each storage element being configurable in an analog mode in which a stored signal at the storage node of the storage element is changed continuously in response to the output signal of the second charge pump (CP 2 ) and each storage element is configurable in a digital mode in which the stored value is one value out of a predetermined set of values and the storage element being further configured to assume the analog mode if a preceding storage element and a subsequent storage element are in the digital mode and have different values of the stored signal, and wherein at least two storage elements share a storage capacitance for storing the stored signal at the storage node.