Charge pump with current limiting circuit

摘要

A charge pump power supply includes two or more modes of operation. An input protection circuit is connected between an input of the power supply and a voltage source. The input protection circuit regulates the voltage at the input of the power supply, limits current at the input when switching from a weaker mode to a stronger mode, and prevents current reversal when switching from a stronger mode to a weaker mode. In some modes, the power supply continuously provides current to the load, obviating the need for an output capacitor.