Tri-state charge pump

A phase locked loop comprising:

• an integrated circuit (“IC”) having an input and a single-pin output at which an output voltage is generated that has at least a minimum value and a maximum value;
• a charge pump circuit for extending the range of said IC output, comprising,
• a switching circuit coupled to said single-pin IC output, comprising a first circuit for generating a first signal as a function of the maximum value of said output voltage and a second circuit for generating a second signal as a function of the minimum value of said output voltage, and
• an output circuit comprising a current source circuit coupled to said first circuit and configured for operating in an active or inactive state and a current sink circuit coupled to said second circuit and configured for operating in an active or inactive state, wherein said first signal causes said current source circuit to operate in its active state for generating a charge current that can be translated into a first voltage having a maximum saturation value that is larger than the maximum value of said IC output voltage, and said second signal causes said current sink circuit to operate in its active state for generating a discharge current that can be translated into a second voltage having a value that is about the same as or smaller than the minimum value of said IC output voltage;
• a filter circuit coupled to said charge pump circuit for translating said charge current into said first voltage and for translating said discharge current into said second voltage;
• and
• a voltage controlled oscillator circuit coupled between said filter circuit and the input to said IC.