Patent attributes
A charge pump configured for use in a phase-locked loop includes positive and negative current sources, transistor switches, voltage nodes and one or more operational amplifiers, wherein the positive and negative current sources each includes an output node, the output nodes are respectively connected sequentially to the voltage nodes having substantially the same voltage, the transistor switches are configured to sequentially switch such that at all times there is one transistor switch connection, and the currents flows through the transistor switches into one of the voltage nodes. One of the voltage nodes is connected to the PLL filter and the transistor switches are connected to the PLL filter and are controlled by the phase error pulses. Two voltage nodes are possible. The second node provides feedback. The currents to the second node are supplied substantially simultaneously for the same amount of time.
