CHARGE PUMP APPARATUS

摘要

PURPOSE: To obtain a charge pump circuit in which the output can reach a level higher than the breakdown voltage of oxide between the gate terminal and the source-drain terminal of an MOS capacitor. CONSTITUTION: The charge pump comprises a first MOSFET capacitor C1 (pumping operation capacitor), two other MOSFET capacitors C3 , C4 (back- to-back capacitor) connected together with the common joint of back-to-back capacitors connected in series with the pumping operation capacitor, a voltage clamp M1 connected with the common node of all three MOSFET capacitors, and a diode 350 for outputting through a pumping operation. A large number of these charge pump circuits may be cascaded to form a multistage charge pump circuit. Each charge pump circuit may reach an output voltage higher than the oxide breakdown voltage of the individual MOS capacitor.