Variation tolerant charge leakage correction circuit for phase locked loops

摘要

The present invention provides for compensation of leakage charge in a PLL. A first plurality and second plurality of charge pumps has a source charge pump and a sink charge pump, and each charge pump has its own switch. A first node is coupled between at least one source charge pump and at least one sink charge pump. A second node coupled between at least one source charge pump and at least one sink charge pump. A PLL filter is coupled to the first node. A dummy filter is coupled to the second node. A first input of a differential mode sensor is coupled to the PLL filter. A second input of a differential mode sensor is coupled to the dummy filter. A first input of a common mode sensor is coupled to the dummy filter. A second input of a common mode sensor coupled to the PLL filter.