An alternating-current (AC) voltage regulator including an isolated power supply, a control circuit, an amplifier, and an output. The isolated power supply is configured to receive an input voltage and output a direct-current (DC) signal isolated from the input voltage. The control circuit is configured to adjust a portion of the input voltage, and output an adjusted voltage. The amplifier is configured to output a differential signal. The differential signal is based on at least one selected from a group consisting of the isolated DC signal, the adjusted voltage, and a feedback loop. The output is configured to add the differential signal to the input voltage resulting in a regulated voltage, and output the regulated voltage.

A power source circuit includes: a plurality of power supply circuits which are electrically connected to different positions in a power supply wiring through which power is supplied to a plurality of processing circuits, wherein each of the power supply circuits is configured to generate a power supply voltage with reference to an input reference voltage, and supply the power supply voltage to the power supply wiring; and a reference voltage supply circuit generate a plurality of reference voltages with different voltages and to each of the plurality of power supply circuits, supply one of the different reference voltages as the input reference voltage thereof.

An alternating-current (AC) voltage regulator including an input, an isolated power supply, a control circuit, an amplifier, and an output. The input is configured to receive an input voltage. The isolated power supply is configured to receive the input voltage and output a direct-current (DC) signal isolated from the input voltage. The control circuit is configured to receive a portion of the input voltage, adjust the portion of the input voltage, and output the adjusted voltage. The amplifier is configured to receive the isolated DC signal, the adjusted voltage, and a feedback loop, and output a differential signal. The output is configured to add the differential signal to the input voltage resulting in a regulated voltage, and output the regulated voltage.

An alternating-current (AC) voltage regulator including an input, an isolated power supply, a control circuit, an amplifier, and an output. The input is configured to receive an input voltage. The isolated power supply is configured to receive the input voltage and output a direct-current (DC) signal isolated from the input voltage. The control circuit is configured to receive a portion of the input voltage, adjust the portion of the input voltage, and output the adjusted voltage. The amplifier is configured to receive the isolated DC signal, the adjusted voltage, and a feedback loop, and output a differential signal. The output is configured to add the differential signal to the input voltage resulting in a regulated voltage, and output the regulated voltage.

A voltage regulator can include: an input port with two terminals, and being configured to receive an input voltage; an output port with two terminals, and being configured to generate an output voltage, where the input port and the output port have a common ground potential; a group of input switches coupled in series between the two terminals of the input port, where a common node of every two adjacent input switches that form an input half-bridge topology is taken as an input switch node; at least one output half-bridge topology coupled between two terminals of the output port, where a common node of a high-side output switch and a low-side output switch in each output half-bridge topology is taken as an output switch node; and N storage capacitors, where each of the storage capacitors is coupled between one input switch node and one output switch node.

A voltage regulator can include: an input port with two terminals, and being configured to receive an input voltage; an output port with two terminals, and being configured to generate an output voltage, where the input port and the output port have a common ground potential; a group of input switches coupled in series between the two terminals of the input port, where a common node of every two adjacent input switches that form an input half-bridge topology is taken as an input switch node; at least one output half-bridge topology coupled between two terminals of the output port, where a common node of a high-side output switch and a low-side output switch in each output half-bridge topology is taken as an output switch node; and N storage capacitors, where each of the storage capacitors is coupled between one input switch node and one output switch node.

A constant voltage circuit amplifies an error between a reference voltage and an output voltage by an operational amplifier, and controls a load current based on the amplified voltage so that the output voltage becomes a constant voltage. The constant voltage circuit includes voltage detector means that detects only AC components of the output voltage limited to a predetermined band and outputs a detected voltage; voltage amplifier means that amplifies AC components of the detected voltage and outputs an amplified voltage; judgment means that outputs a judgment signal indicating whether or not the amplified voltage equal to or larger than a predetermined threshold; and controller means configured to increase a current value of the constant current source included in the operational amplifier, based on the judgment signal, thereby temporarily increasing a current consumption of the operational amplifier.

A constant voltage circuit amplifies an error between a reference voltage and an output voltage by an operational amplifier, and controls a load current based on the amplified voltage so that the output voltage becomes a constant voltage. The constant voltage circuit includes voltage detector means that detects only AC components of the output voltage limited to a predetermined band and outputs a detected voltage; voltage amplifier means that amplifies AC components of the detected voltage and outputs an amplified voltage; judgment means that outputs a judgment signal indicating whether or not the amplified voltage equal to or larger than a predetermined threshold; and controller means configured to increase a current value of the constant current source included in the operational amplifier, based on the judgment signal, thereby temporarily increasing a current consumption of the operational amplifier.

An alternating-current (AC) voltage regulator configured to receive an input voltage. The regulator including an AC/DC pulse-width modulated (PWM) power supply configured to receive the input voltage and output a direct-current (DC) signal isolated from the input voltage. The regulator including a control circuit configured to receive a portion of the input voltage, adjust an amplitude and a phase of the portion of the input voltage, and output the adjusted voltage. The regulator including an amplifier configured to receive, via an power input, the isolated DC signal; receive, via a first input, the adjusted voltage; receive a feedback loop from an amplifier output to a second input; and output, via the amplifier output, a differential signal. The regulator including an output configured to add the differential signal to the input voltage resulting in a regulated voltage, and output the regulated voltage.

An alternating-current (AC) voltage regulator configured to receive an input voltage. The regulator including an AC/DC pulse-width modulated (PWM) power supply configured to receive the input voltage and output a direct-current (DC) signal isolated from the input voltage. The regulator including a control circuit configured to receive a portion of the input voltage, adjust an amplitude and a phase of the portion of the input voltage, and output the adjusted voltage. The regulator including an amplifier configured to receive, via an power input, the isolated DC signal; receive, via a first input, the adjusted voltage; receive a feedback loop from an amplifier output to a second input; and output, via the amplifier output, a differential signal. The regulator including an output configured to add the differential signal to the input voltage resulting in a regulated voltage, and output the regulated voltage.