Patent ID: 7091630

Claim:
A device connected to a power supply and a load circuit to inhibit power supply voltage fluctuation that is caused by fluctuation of a load current generated by the load circuit, the device comprising: a current consumption circuit connected to the power supply and the load circuit to generate a consumption current that flows parallel to the load current of the load circuit; and a current control circuit connected to the current consumption circuit to control the consumption current of the current consumption circuit in order to inhibit fluctuation of an output current of the power supply, which is the sum of the load current and the consumption current, when the load current rises and falls, and wherein the current control circuit includes, a data generation circuit for generating a digital signal that controls the consumption current of the current consumption circuit in order to inhibit fluctuation of the output current of the power supply, and a D/A converter connected to the data generation circuit and the current consumption circuit to convert the digital signal to an analog signal and provide the analog signal to the current consumption circuit, wherein the current control circuit receives a first activation signal for controlling the rising and falling of the load current, a second activation signal provided before the first activation signal, and a clock signal, and wherein the current control circuit generates the digital signal for causing the consumption current to gradually rise by performing an adding operation with the second activation signal and the clock signal, the digital signal for causing the consumption current to fall in synchronism with the rising of the load current in accordance with the first activation signal, and the digital signal for causing the consumption current to gradually fall by performing a subtracting operation with the clock signal.