Regulated charge pump circuit

A method for regulating voltage, the method comprising:

• generating a control signal having a voltage level as a function of an output voltage on a load capacitor by (i) generating a voltage based on a comparison of the output voltage to a reference voltage, (ii) buffering the voltage to output a buffered voltage, and (iii) combining the buffered voltage with multi-phase clock signals to generate the control signal;
• providing the control signal to a switch network circuit that is coupled with the load capacitor and a flying capacitor to form a charge pump circuit;
• charging the flying capacitor in a charge stage;
• providing a pump control voltage to the flying capacitor in a pump stage, the pump control voltage having a voltage level that is adjusted based on the control signal to maintain the output voltage to be stable;
• and
• generating the multi-phase clock signals to control the switch network circuit to enter the charge stage and to enter the pump stage.

An integrated circuit (IC) chip, comprising:

• a voltage regulator that comprises:
• a control signal generator circuit configured to generate a control signal with a voltage level that is a function of an output voltage on a load capacitor, the control signal generator circuit including (i) an operational transconductance amplifier (OTA) coupled with a capacitor, the operational transconductance amplifier configured to output a current based on the output voltage and a reference voltage to charge the capacitor to generate the voltage on the capacitor, (ii) a voltage buffer configured to buffer the voltage and output a buffered voltage, and (iii) a logic circuit configured to combine the buffered voltage with multi-phase clock signals to generate the control signal;
• and
• a switch network circuit coupled with the load capacitor and a flying capacitor to form a charge pump circuit, the switch network circuit being configured to charge the flying capacitor in a charge stage and to pump the flying capacitor in a pump stage to generate the output voltage on the load capacitor, the switch network circuit configured to provide a pump control voltage to the flying capacitor during the pump stage, the pump control voltage having a voltage level that is adjusted based on the control signal to maintain the output voltage to be stable;
• one or more functional circuits that are powered up by the output voltage on the load capacitor;
• and
• a clock generator circuit configured to generate the multi-phase clock signals to control the switch network circuit to enter the charge stage and to enter the pump stage.