In a memory, e.g., a flash memory, sometimes the voltage level of a word line needs to be boosted to a level higher than a power supply voltage VCC in order to compensate for the variation of a memory cell current due to process limitations and also to more efficiently complete a function, e.g., a read function. Once the word line voltage is boosted, some circuits use a continuous charge pump operation to sustain the boosted voltage level by continuously supplying current. However, continuous charge pump operation results in extra power consumption.