Internal power supply circuit for generating internal power supply potential by lowering external power supply potential

摘要

An internal power supply circuit includes a main internal power supply potential generating circuit for generating an internal power supply potential based on a prescribed reference potential, and an auxiliary internal power supply potential generating circuit which is activated in response to a control signal and when activated, generating an internal power supply potential together with the main internal power supply potential generating circuit. The auxiliary internal power supply potential generating circuit includes a P channel MOS transistor for driving, a differential amplifying circuit for controlling the driving transistor by comparing the internal power supply potential with the reference potential and a standby potential supplying circuit for applying a standby potential which is slightly higher than the threshold potential at the which the transistor is rendered conductive, to the gate of the driving transistor while the differential amplifying circuit is not activated. In the internal power supply circuit, since a standby potential which is slightly higher than the threshold potential is applied to the gate of the driving transistor at the standby state, charges are immediately supplied to an output node when the auxiliary internal power supply potential generating circuit is activated.