OVERBOOSTING PREVENTION CIRCUIT

摘要

PROBLEM TO BE SOLVED: To prevent malfunction in an overboosting prevention circuit which prevents a boosting circuit from being overboosted by removing ripples occurring in the boosting circuit.;SOLUTION: The overboosting prevention circuit controls the output voltage Vout (0V) of a charge pump circuit so that a difference (Vdd-Vout) between the power supply voltage Vdd and the output voltage Vout (0V) of the charge pump circuit 2 does not exceed a predetermined value VMAX. That is, the charge pump circuit 2 performs boosting operation when Vdd-VoutVMAX, and stops the boosting operation when Vdd-VoutVMAX. An influence of the ripples caused in the charge pump circuit 2 is removed because the reference voltage Vref to an operational amplifier is determined relative to a ground voltage Vss.;COPYRIGHT: (C)2007,JPO&INPIT