Regulated Charge Pump with Adaptive Drive Strength

An integrated circuit comprising:

• a control interface coupled to a first plurality of integrated circuit pins;
• a plurality of level shifters coupled to the control interface;
• a plurality of radio frequency (RF) switches respectively coupled between the plurality of level shifters and a second plurality of integrated circuit pins;
• and
• at least one regulated charge pump coupled to the plurality of level shifters, wherein the at least one regulated charge pump comprises:
• an amplifier having first and second inputs, the second input configured to receive a reference voltage;
• a clock generator having an input coupled to an output of the amplifier;
• a first open-loop charge pump in a first feedback path having an input coupled to a first output of the clock generator, and an output coupled to the first input of the amplifier;
• and
• a second open-loop charge pump in a second feedback path having an input coupled to a second output of the clock generator, and an output coupled to the first input of the amplifier,
• wherein the output of the first open-loop charge pump and the output of the second open-loop charge pump comprises an output of the regulated charge pump, and wherein the first output of the clock generator is configured for providing a first clock signal having a first frequency, and wherein the second output of the clock generator is configured for providing a second clock signal having a second frequency different from the first frequency.

A method comprising:

• amplifying a charge pump output voltage to a reference voltage to generate an enable signal;
• generating a first clock signal and a second clock signal in response to the enable signal;
• generating the charge pump output voltage with a first charge pump responsive to the first clock signal;
• counting a number of periods of the second clock signal;
• and
• boosting a driving strength of the first charge pump with a second charge pump, wherein a number of pumping stages of the second charge pump are enabled according to the number of periods that are counted.