In a power supply voltage converting circuit using a charge pump circuit having a switch device (Nch MOS transistor Qn(12) and Pch MOS transistor Qp(12)) in an output unit, a first clamp circuit (13) diode-clamps a switching pulse voltage (control pulse voltage) for the switch device at the time of starting...http://www.google.de/patents/US7205989?utm_source=gb-gplus-sharePatent US7205989 - Power supply voltage converting circuit control method thereof display apparatus and portable terminal
