Abstract: Provided is a controller that is capable of reducing fall in a waveform of a power supply voltage when the power supply voltage supplied to a CPU is reduced. A controller for controlling voltage regulators includes a differential amplifier that outputs a measurement voltage corresponding to a power supply voltage supplied to a load and an error amplifier having a non-inverting input terminal supplied with a target voltage and an inverting input terminal supplied with a measurement voltage. The error amplifier compares the target voltage and the measurement voltage and outputs a signal for controlling the voltage regulators. Further included in the controller is a correction circuit that applies an offset voltage to the inverting input terminal of the error amplifier when the power supply voltage supplied to the load is reduced.

Abstract: The disclosed invention provides a controller that can prevent overshoot and undershoot from occurring when a voltage is switched to another voltage without using two types of regulators. Voltage regulators supply a power supply voltage to a CPU. An SVID interface receives a command to change the number of voltage regulators to be actuated among the voltage regulators from outside. A phase clock generating circuit makes a stepwise change of the number of voltage regulators to be actuated from the current number of regulators to the commanded number of regulators after change.

Abstract: The disclosed invention provides a controller that can prevent overshoot and undershoot from occurring when a voltage is switched to another voltage without using two types of regulators. Voltage regulators supply a power supply voltage to a CPU. An SVID interface receives a command to change the number of voltage regulators to be actuated among the voltage regulators from outside. A phase clock generating circuit makes a stepwise change of the number of voltage regulators to be actuated from the current number of regulators to the commanded number of regulators after change.

Abstract: Provided is a controller that is capable of reducing fall in a waveform of a power supply voltage when the power supply voltage supplied to a CPU is reduced. A controller for controlling voltage regulators includes a differential amplifier that outputs a measurement voltage corresponding to a power supply voltage supplied to a load and an error amplifier having a non-inverting input terminal supplied with a target voltage and an inverting input terminal supplied with a measurement voltage. The error amplifier compares the target voltage and the measurement voltage and outputs a signal for controlling the voltage regulators. Further included in the controller is a correction circuit that applies an offset voltage to the inverting input terminal of the error amplifier when the power supply voltage supplied to the load is reduced.