Internal power source voltage generating circuit of semiconductor memory and method for generating internal power source voltage

An internal power source voltage generating circuit of a semiconductor memory to generate an internal power source voltage so as to drive a semiconductor memory based on an external power source voltage, comprising:

• a first boosting part to supply a boosted voltage in which the external power source voltage is boosted to the semiconductor memory as the internal power source voltage via an output line;
• and
• a second boosting part comprising a condenser having one end connected to the output line, and a boost driving control circuit wherein while a reference low potential is applied to the other end of the condenser, the external power source voltage is applied to the output line so as to perform a charging operation to charge the condenser, and if the internal power source voltage is lower than a threshold voltage, the external power source voltage is applied to the other end of the condenser, thereby raising a potential of the other end of the condenser.