US Patent 10491114 Output regulated charge pump

An output regulated charge pump including a low drop out (LDO) regulator configured to output a variable first output voltage, a multi-stage charge pump configured to receive the variable first output voltage and produce a second output voltage to power a load, a first feedback circuit configured to compare the second output voltage to a reference voltage, and a second feedback circuit configured to measure level of current used by the load, wherein the second feedback circuit outputs a level select signal to the LDO that is configured to vary a level of the first output voltage and reduce charge pump output ripple.