High efficiency charge pump circuit

摘要

An integrated circuit device includes a charge pump to provide current at a potential which is greater than a supply potential. A potential maintenance circuit gates on when the potential at the output of the charge pump circuit drops to a level which is below VCC. The potential maintenance circuit permits the charge pump can be bypassed or designed to provide a minimum current output. An overvoltage shutoff circuit permits the charge pump to be effectively bypassed when supply voltage is sufficiently high to make bypass desireable.