Patent ID: 7550954

Claim:
A voltage regulator for power provided from a main external battery having a vbat voltage to a vout load terminal for an external load, comprising: a low drop-out-voltage (LDO) voltage regulator coupled between the main external battery and the vout load terminal, when the voltage at the vout load terminal is less than the voltage of the main external battery, said low drop out voltage LDO regulator including a vreg output terminal; a charge pump circuit adapted to be connected in a feedback loop between said low drop out voltage LDO regulator and the vout load terminal, when the voltage at the vout load terminal exceeds the voltage of the main external battery; and wherein the charge pump circuit includes: an input terminal coupled to said vreg output terminal of the low drop out LDO voltage regulator; and an output terminal coupled to the vout output load terminal.