| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent a step-down power supply voltage VDD from rising after a pull-down operation in a step-down power supply device of the type having a pull-down circuit in order to deal with sudden increases in the current consumed by peripheral circuits. <P>SOLUTION: The step-down power supply device includes a comparator 201 for comparing a reference voltage to an internal power supply voltage; a driver 202 connected at its input to an external power supply voltage VCC and at its control input to a control node G0 connected to the output of the comparator, with the output of the driver being connected to a step-down voltage node so that a voltage at a value matching the voltage of the control node G0 is outputted to the step-down voltage node as an internal power supply voltage VDD; a pull-down circuit 203 that connects the control node G0 to a ground voltage for a first period of time when an activation signal for activating load is inputted from the outside; and a pull-up circuit 204 that connects the control node G0 to an external power supply voltage VCC for a second period of time after the control node G0 has been connected to the ground voltage for the first period of time. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
