Charge pump DC/DC converters with reduced input noise

A method for regulating a voltage at an output node of a boost voltage regulator, the method comprising:

• providing a first capacitor;
• providing a first switch coupled between the first capacitor and the output node;
• providing a second switch coupled to the first capacitor;
• controlling the first and second switches to alternately charge the first capacitor from an input voltage and discharge the first capacitor to the output node;
• monitoring the voltage at the output node to generate a control signal;
• and
• controlling the current flowing through the first capacitor in response to the control signal when the first switch is closed, by providing a variable resistance in series between the input voltage and the first capacitor when the first switch is closed,
• wherein the variable resistance is responsive to the control signal.

A method for regulating a voltage at an output node of a boost voltage regulators the method comprising:

• providing a first capacitor;
• providing a first switch coupled between the first capacitor and the output node;
• providing a second switch coupled to the first capacitor;
• controlling the first and second switches to alternately charge the first capacitor from an input voltage and discharge the first capacitor to the output node;
• monitoring the voltage at the output node to generate a control signal;
• controlling the current flowing through the first capacitor in response to the control signal when the first switch is closed;
• and
• controlling the current through the first capacitor in response to the control signal when the second switch is closed,
• by providing a variable resistance in series between the input voltage and the first capacitor when the second switch is closed.

A method for regulating a voltage at an output node of a boost voltage regulator, the method comprising:

• providing a first capacitor;
• providing a first switch coupled between the first capacitor and the output node;
• providing a second switch coupled to the first capacitor;
• controlling the first and second switches to alternately charge the first capacitor from an input voltage and discharge the first capacitor to the output node;
• monitoring the voltage at the output node to generate a control signal;
• controlling the current flowing through the first capacitor in response to the control signal when the first switch is closed,
• by providing a current mirror, wherein current flows from the input voltage through the current mirror to the first capacitor.

A method for regulating a voltage at an output node of a boost voltage regulator, the method comprising:

• providing a first capacitor;
• providing a first switch coupled between the first capacitor and the output node;
• providing a second switch coupled to the first capacitor;
• controlling the first and second switches to alternately charge the first capacitor from an input voltage and discharge the first capacitor to the output node;
• monitoring the voltage at the output node to generate a control signal;
• controlling the current flowing through the first capacitor in response to the control signal when the first switch is closed;
• controlling the current through the first capacitor in response to the control signal when the second switch is closed by providing a first current mirror that conducts current when the second switch is closed;
• and
• wherein controlling the current flowing through the first capacitor in response to the control signal when the first switch is closed comprises providing a second current mirror that conducts current when the first switch is closed.

A method for regulating a voltage at an output node of a buck voltage regulator, the method comprising:

• providing first and second capacitors;
• providing a first switch coupled to the first capacitor and a second switch coupled to the second capacitor;
• switching the first switch to charge the first capacitor from an input voltage;
• switching the second switch out of phase with the first switch to charge the second capacitor from the input voltage;
• monitoring the voltage at the output node to generate a control signal;
• and
• controlling the current flowing through the first capacitor in response to the control signal when the first switch is closed and controlling the current flowing through the second capacitor in response to the control signal when the second switch is closed.

A method for regulating a voltage at an output node of a buck voltage regulator, the method comprising:

• providing first and second capacitors;
• providing a first switch coupled to the first capacitor and a second switch coupled to the second capacitor;
• switching the first switch to charge the first capacitor from an input voltage;
• switching the second switch out of phase with the first switch to charge the second capacitor from the input voltage;
• monitoring the voltage at the output node to generate a control signal;
• and
• controlling the current flowing through the first capacitor in response to the control signal when the first switch is closed and controlling the current flowing through the second capacitor in response to the control signal when the second switch is closed,
• by providing a current mirror.

A method for regulating a voltage at an output node of a buck voltage regulator, the method comprising:

• providing first and second capacitors;
• providing a first switch coupled to the first capacitor and a second switch coupled to the second capacitor;
• switching the first switch to charge the first capacitor from an input voltage;
• switching the second switch out of phase with the first switch to charge the second capacitor from the input voltage;
• monitoring the voltage at the output node to generate a control signal;
• controlling the current flowing through the first capacitor in response to the control signal when the first switch is closed and controlling the current flowing through the second capacitor in response to the control signal when the second switch is closed;
• providing third and fourth switches that are each coupled between the first capacitor and the output node;
• providing a fifth switch coupled to the first capacitor;
• providing sixth and seventh switches that are each coupled between the second capacitor and the output node;
• and
• providing an eighth switch coupled to the second capacitor.

A boost voltage regulator that regulates a voltage at an output node, comprising:

• a first capacitor;
• a first switch coupled between the first capacitor and the output node;
• a second switch coupled to the first capacitor, wherein current alternately flows from an input voltage to the first capacitor and from the first capacitor to the output node;
• feedback loop circuitry that monitors the voltage at the output node and generates a control signal;
• and
• a transistor that controls the current flowing through the first switch in response to the control signal when the first switch is closed.

A boost voltage regulator that regulates a voltage at an output node, comprising:

• a first capacitor;
• a first switch coupled between the first capacitor and the output node;
• a second switch coupled to the first capacitor, wherein current alternately flows from an input voltage to the first capacitor and from the first capacitor to the output node;
• feedback loop circuitry that monitors the voltage at the output node and generates a control signal;
• and
• a transistor that controls the current flowing through the first switch in response to the control signal when the first switch is closed,
• wherein the transistor controls the current through the second switch in response to the control signal when the second switch is closed,
• wherein the transistor comprises a variable resistance coupled in series between the input voltage and the first capacitor when the second switch is closed, and
• wherein the variable resistance is responsive to the control signal.

A boost voltage regulator that regulates a voltage at an output node, comprising:

• a first capacitor;
• a first switch coupled between the first capacitor and the output node;
• a second switch coupled to the first capacitor, wherein current alternately flows from an input voltage to the first capacitor and from the first capacitor to the output node;
• feedback loop circuitry that monitors the voltage at the output node and generates a control signal;
• a transistor that controls the current flowing through the first switch in response to the control signal when the first switch is closed,
• wherein the transistor is part of a first current mirror that controls the current through the first switch in response to the control signal when the first switch is closed;
• and the regulator further comprises:
• a second current mirror that controls the current through the second switch in response to the control signal when the second switch is closed.

A buck voltage regulator that regulates a voltage at an output node, comprising:

• first and second capacitors;
• a first switch coupled to the first capacitor;
• a second switch coupled to the second capacitor that is switched out of phase with the first switch, wherein current alternately flows from an input voltage to the first capacitor and from the input voltage to the second capacitor;
• feedback loop circuitry that monitors the voltage at the output node to generate a control signal;
• and
• a transistor that controls the current through the first switch when it is closed and the current through the second switch when it is closed in response to the control signal.

A buck voltage regulator that regulates a voltage at an output node, comprising:

• first and second capacitors;
• a first switch coupled to the first capacitor;
• a second switch coupled to the second capacitor that is switched out of phase with the first switch, wherein current alternately flows from an input voltage to the first capacitor and from the input voltage to the second capacitor;
• feedback loop circuitry that monitors the voltage at the output node to generate a control signal;
• a transistor that controls the current through the first switch when it is closed and the current through the second switch when it is closed in response to the control signal,
• wherein the transistor comprises a variable resistance.

A buck voltage regulator that regulates a voltage at an output node, comprising:

• first and second capacitors;
• a first switch coupled to the first capacitor;
• a second switch coupled to the second capacitor that is switched out of phase with the first switch, wherein current alternately flows from an input voltage to the first capacitor and from the input voltage to the second capacitor;
• feedback loop circuitry that monitors the voltage at the output node to generate a control signal;
• a transistor that controls the current through the first switch when it is closed and the current through the second switch when it is closed in response to the control signal;
• third and fourth switches that are each coupled between the first capacitor and the output node;
• a fifth switch coupled to the first capacitor;
• sixth and seventh switches that are each coupled between the second capacitor and the output node;
• an eighth switch coupled to the second capacitor;
• and
• a third capacitor coupled to the fifth switch;
• a ninth switch coupled between the third capacitor and the output node;
• a tenth switch coupled between the third capacitor and ground;
• and
• an eleventh switch coupled to the third capacitor.