| 摘要 |
PURPOSE: A high voltage generator is provided to achieve a low power operation by minimizing the waste of power consumed unnecessarily in a charge pumping, by controlling to generate a high voltage power using not a charge pumping but an external power supply within the range of an operation voltage of a chip. CONSTITUTION: According to the voltage generator, a Vpp detecting unit(210) detects a high voltage from an output stage and detects whether the high voltage is lower than a voltage level fixed by a user. An oscillation unit(220) generates a pulse signal(osc) to control a charge pumping operation periodically according to the voltage level of the high voltage and is connected to an output stage of the Vpp detecting unit. A pumping unit(230) performs the charge pumping operation under the control of the pulse signal. A Vext detecting unit(215) detects an external power supply voltage and detects whether the external power supply voltage is higher than a voltage level fixed by the user. A Vpp voltage level shifting unit(240) shifts the high voltage level by receiving a signal generated by an OR operation of the output signals of the Vpp detecting unit and the Vext detection unit. An operational amplification unit(250) is activated by a row control signal(ctrl). A switching unit(260) controls to select a voltage level of the high voltage being output finally by connecting the pumping unit with an output stage of the operational amplification unit, and a precharge unit(270) precharges the high voltage during a standby mode by being connected between the external power supply voltage applying stage and the high voltage output stage.
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