| CPC H03L 7/0895 (2013.01) [H03L 7/087 (2013.01); H03L 7/099 (2013.01)] | 18 Claims |

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1. A charge pump circuit comprising:
an H-bridge circuit; an input of the H-bridge circuit coupled to a phase frequency detector to receive respective increment and decrement control signals from the phase frequency detector;
an output of the H-bridge circuit coupled to a loop filter to control current flow to and from the loop filter based on the respective increment and decrement control signals;
a first loop control comprising a sense operational amplifier coupled to the H-bridge circuit, wherein the sense operational amplifier provides an output configured to drive a pair of H-bridge footer transistors providing a charge pump current to match respective voltages at a first charge pump node and a second charge pump node; and
a second loop control coupled to the H-bridge circuit configured to drive an H-bridge header transistor to adjust a common mode voltage at the second charge pump node and a third charge pump node, the second charge pump node and the third charge pump node coupled to the loop filter.
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