Charge pump circuit with dynamic biasing of pass transistors

A two-phase charge pump capable of being controlled by first and second clock signals that are in phase-opposition, the charge pump comprising:

• two branches that each include a plurality of cascade-connected stages, each of the stages of one branch having a corresponding stage in the other branch, and each of the stages of the one branch being coupled to the corresponding stage in the other branch, each of the stages including:
• a capacitive element driven by one of the clock signals such that the capacitive elements of adjacent stages of each branch are driven by different clock signals;
• a pass transistor coupled to the capacitive element of the stage, the pass transistor selectively transferring electric charge to the capacitive element of the stage from the capacitive element of a previous stage;
• a first biasing circuit enabling the pass transistor of the stage during a first phase of the one clock signal, the first biasing circuit coupling an input voltage of the corresponding stage to the pass transistor of the stage;
• and
• a second biasing circuit disabling the pass transistor of the stage during a second phase of the one clock signal.

A two-phase charge pump capable of being controlled by first and second clock signals that are in phase-opposition, the charge pump comprising:

• a plurality of cascade-connected stages, each of the stages including:
• a capacitive element driven by one of the clock signals such that the capacitive elements of each pair of adjacent stages are driven by different clock signals;
• a pass transistor coupled to the capacitive element of the stage, the pass transistor selectively transferring electric charge to the capacitive element of the stage from the capacitive element of a previous stage;
• a first biasing transistor enabling the pass transistor of the stage during a first phase of the one clock signal, the first biasing transistor coupling the one clock signal to the pass transistor of the stage, the first biasing circuit being active during an entire semi-period in which the pass transistor is conductive, and the first biasing circuit supplying the one clock signal directly to a gate of the pass transistor so as to directly bias the gate of the pass transistor;
• and
• a second biasing transistor disabling the pass transistor of the stage during a second phase of the one clock signal.

A two-phase charge pump capable of being controlled by first and second clock signals that are in phase-opposition, the charge pump comprising:

• two branches that each include a plurality of cascade-connected stages, each of the stages of one branch having a corresponding stage in the other branch, and each of the stages of the one branch being coupled to the corresponding stage in the other branch, each of the stages including:
• a capacitive element driven by one of the clock signals such that the capacitive elements of adjacent stages of each branch are driven by different clock signals;
• a pass transistor coupled to the capacitive element of the stage, the pass transistor selectively transferring electric charge to the capacitive element of the stage from the capacitive element of a previous stage;
• a first biasing transistor enabling the pass transistor of the stage during a first phase of the one clock signal, the first biasing transistor coupling an input voltage of the corresponding stage to the pass transistor of the stage;
• and
• a second biasing transistor disabling the pass transistor of the stage during a second phase of the one clock signal.

A method of operating a two-phase charge pump controlled by first and second clock signals that are in phase-opposition, the charge pump having a plurality of cascade-connected stages, the method comprising, for each of the stages, the steps of:

• driving a capacitive element with one of the clock signals such that the capacitive elements of each pair of adjacent stages are driven by different clock signals;
• selectively transferring electric charge to the capacitive element of the stage from the capacitive element of a previous stage through a pass transistor;
• enabling the pass transistor of the stage during a first phase of the one clock signal and disabling the pass transistor of the stage during a second phase of the one clock signal;
• causing a first biasing circuit to be active during an entire semi-period in which the pass transistor is conductive;
• and
• supplying the one clock signal from the first biasing circuit directly to a gate of the pass transistor so as to directly bias the gate of the pass transistor.

A method of operating a two-phase charge pump controlled by first and second clock signals that are in phase-opposition, the charge pump having two branches that each include a plurality of cascade-connected stages, the method comprising, for each of the stages, the steps of:

• driving a capacitive element with one of the clock signals such that the capacitive elements of adjacent stages are driven by different clock signals;
• selectively transferring electric charge to the capacitive element of the stage from the capacitive element of a previous stage through a pass transistor;
• and
• enabling the pass transistor of the stage during a first phase of the one clock signal and disabling the pass transistor of the stage during a second phase of the one clock signal,
• wherein each of the stages of one branch has a corresponding stage in the other branch, and each of the stages of the one branch is coupled to the corresponding stage in the other branch.