Patent ID: 7839205
Filing Date: 2010-11-23
Classification: G05F,G11C

Abstract:
1. A step-down circuit connected between a power supply node that supplies a supply voltage and an internal power supply line, to produce a step-down voltage from the supply voltage and apply the step-down voltage to an object circuit through the internal power supply line, the step-down circuit comprising: a comparison circuit that compares a reference voltage with a voltage of the internal power supply line, said comparison circuit including a first current path activated by a first signal and a second current path activated by a second signal; and a driver that adjusts a current flowing between the internal power supply line and the power supply node according to a comparison result of the comparison circuit, wherein an activity level of the driver is controlled to rise to a predetermined high period synchronously with an activated operation of the object circuit in response to the reference voltage and a current of said first current path and fall to a predetermined low period that comes after the high period in response to the reference voltage and a current of said second current path.