Patent ID: 8456208

Claim:
A charge pump comprising: a) a capacitor; a first input to connect to a first power supply; a second input to connect to a second power supply having a voltage lower than the first power supply, a two output phase detector; a first bias input to connect to a first bias voltage; and a second bias input to connect to a second bias voltage; and, b) a pump up current path comprising a first transistor connected between said first input and a first intermediate node the gate connected to the first output of said phase detector, and a second transistor connected between the first intermediate node and said capacitor the gate connected to said first bias input; and, c) a pump down current path comprising a third transistor connected between said second input and a second intermediate node the gate connected to the second output of said phase detector, and a fourth transistor connected between the second intermediate node and the capacitor the gate connected to said second bias input; and, d) a first alternate current path connected between the first intermediate node and said second input configured to conduct current for a brief period of time when said first transistor is switched to an off state; and, e) a second alternate current path connected between the second intermediate node and said first input configured to conduct current for a brief period of time when said third transistor is switched to an off state; wherein said first alternate current path further comprises a fifth transistor connected to the first intermediate node and a third intermediate node; and, a sixth transistor connected to the third intermediate node and the second input; and, said second alternate current path further comprises a seventh transistor connected to the first intermediate node and a fourth intermediate node; and, an eighth transistor connected to the fourth intermediate node and said first input.