Apparatus for charging a capacitor

摘要

An NMOS FET circuit for charging a storage capacitor to a voltage higher than the power supply voltage. The circuit includes several stages each including a capacitance and FET switches. In response to a high level control signal the FET's in effect connect each capacitance between the supply voltage and ground to charge the capacitances. Then, in response to a low level control signal the FET's in effect connect the capacitances in series between the supply voltage and the storage capacitor thus transferring a portion of the charges in the capacitances into the storage capacitor. The charge placed in the storage capacitor produces a voltage thereacross which is greater than the supply voltage.