Abstract: A DCDC circuit according to an embodiment includes a capacitor network, and a smoothing capacitor. The capacitor network includes a first state in which first capacitors are connected onto a wiring path between an input node to which an input voltage is applied and one end of a first coil and a second capacitor is connected between a connection point of the first capacitors on the wiring path and a reference potential point, and a second state in which the second capacitor is connected to one end of a second coil and the first capacitors are connected between one end of the second capacitor and the reference potential point and between the other end of the second capacitor and the reference potential point, respectively.

Abstract: A power supply circuit in an embodiment includes a first transistor controlled to be turned on and off by a control signal supplied to a gate to output an output voltage following a predetermined voltage, a second transistor, one end of a current path of which is connected to an input terminal for supplying a power supply voltage, the second transistor outputting the predetermined voltage according to the control signal, and an amplifier circuit configured to amplify a voltage difference between a reference voltage and the predetermined voltage, and output the voltage difference as the control signal.

Abstract: A power source circuit according to an embodiment includes: first and second transistors connected to a current path between an input terminal and an output terminal; a first node that supplies a first control voltage to a gate of the first transistor; a comparator with a first input terminal to which a voltage supplied to the input terminal is applied and a second input terminal to which a voltage appearing at a second node being a connecting point of respective drains of the first and second transistors is applied, the comparator being configured to compare voltages of the first input terminal and the second input terminal to each other and to control the first control voltage to be supplied to the first node based on a comparison result; and a diode connected between the first input terminal and the second input terminal of the comparator.

Abstract: A power supply circuit in an embodiment includes a first transistor that supplies an output based on an input power supply voltage to a load or stops the supply of the output to the load, a second transistor, one end of a current path of which is connected to the gate of the first transistor and another end of the current path of which is connected to a reference potential point, the second transistor being turned on and off according to a level of a gate voltage of the second transistor, a capacitor connected between an input end of the power supply voltage and a gate of the second transistor, and a voltage holding circuit connected between the gate of the second transistor and the reference potential point and configured to hold the gate voltage of the second transistor.

Abstract: A power supply circuit in an embodiment includes a first transistor controlled to be turned on and off by a control signal supplied to a gate to output an output voltage following a predetermined voltage, a second transistor, one end of a current path of which is connected to an input terminal for supplying a power supply voltage, the second transistor outputting the predetermined voltage according to the control signal, and an amplifier circuit configured to amplify a voltage difference between a reference voltage and the predetermined voltage, and output the voltage difference as the control signal.

Abstract: A power supply circuit in an embodiment includes a first transistor controlled to be turned on and off by a control signal supplied to a gate to output an output voltage following a predetermined voltage, a second transistor, one end of a current path of which is connected to an input terminal for supplying a power supply voltage, the second transistor outputting the predetermined voltage according to the control signal, and an amplifier circuit configured to amplify a voltage difference between a reference voltage and the predetermined voltage, and output the voltage difference as the control signal.

Abstract: A power supply circuit of an embodiment includes a first transistor including a source connected to an input terminal, and a gate connected to a first node; a second transistor including a drain connected to a drain of the first transistor, and a source connected to an output terminal; a third transistor including a source connected to the input terminal, a drain connected to the first node, and a gate connected to a second node; and a Zener diode including an anode connected to the input terminal, and a cathode connected to the second node.

Abstract: A DCDC circuit according to an embodiment includes a capacitor network, and a smoothing capacitor. The capacitor network includes a first state in which first capacitors are connected onto a wiring path between an input node to which an input voltage is applied and one end of a first coil and a second capacitor is connected between a connection point of the first capacitors on the wiring path and a reference potential point, and a second state in which the second capacitor is connected to one end of a second coil and the first capacitors are connected between one end of the second capacitor and the reference potential point and between the other end of the second capacitor and the reference potential point, respectively.

Abstract: A power supply circuit in an embodiment includes a series circuit of a first resistor and a second transistor, the series circuit being connected in parallel to a first transistor between an input terminal and an output terminal, a third transistor configured to output an electric current corresponding to an electric current flowing to the first resistor, a third resistor configured to generate a voltage corresponding to the electric current, and a second operational amplifier configured to output a signal corresponding to a voltage difference between the voltage and a reference voltage to a gate of the first transistor and a gate of the second transistor.

Abstract: A power supply circuit in an embodiment includes a series circuit of a first resistor and a second transistor, the series circuit being connected in parallel to a first transistor between an input terminal and an output terminal, a third transistor configured to output an electric current corresponding to an electric current flowing to the first resistor, a third resistor configured to generate a voltage corresponding to the electric current, and a second operational amplifier configured to output a signal corresponding to a voltage difference between the voltage and a reference voltage to a gate of the first transistor and a gate of the second transistor.

Abstract: A power supply circuit in an embodiment includes a first transistor that supplies an output based on an input power supply voltage to a load or stops the supply of the output to the load, a second transistor, one end of a current path of which is connected to the gate of the first transistor and another end of the current path of which is connected to a reference potential point, the second transistor being turned on and off according to a level of a gate voltage of the second transistor, a capacitor connected between an input end of the power supply voltage and a gate of the second transistor, and a voltage holding circuit connected between the gate of the second transistor and the reference potential point and configured to hold the gate voltage of the second transistor.

Abstract: A power supply circuit in an embodiment includes a first transistor controlled to be turned on and off by a control signal supplied to a gate to output an output voltage following a predetermined voltage, a second transistor, one end of a current path of which is connected to an input terminal for supplying a power supply voltage, the second transistor outputting the predetermined voltage according to the control signal, and an amplifier circuit configured to amplify a voltage difference between a reference voltage and the predetermined voltage, and output the voltage difference as the control signal.

Abstract: According to one embodiment, a semiconductor protection circuit includes a first MOS transistor that has a drain that is connected to an input terminal, a source that is connected to an output terminal, and a gate that is connected to a control terminal, a second MOS transistor that has a drain that is connected to the gate of the first MOS transistor and a source that is connected to the source of the first MOS transistor, a rectifier element that is connected in a forward direction from a gate of the second MOS transistor to the gate of the first MOS transistor, and a low-pass filter that is connected between the gate and the source of the second MOS transistor.

Abstract: According to one embodiment, a power supply circuit includes a smoothing capacitor that is charged with a charge current from an output transistor and outputs a voltage as an output voltage; a control loop that controls a conduction state of the output transistor depending on a difference value between the output voltage and a reference voltage; and a gain adjustment circuit that adjusts a gain of the control loop depending on magnitude of the charge current after the charge starts.

Abstract: According to one embodiment, a semiconductor protection circuit includes a first MOS transistor that has a drain that is connected to an input terminal, a source that is connected to an output terminal, and a gate that is connected to a control terminal, a second MOS transistor that has a drain that is connected to the gate of the first MOS transistor and a source that is connected to the source of the first MOS transistor, a rectifier element that is connected in a forward direction from a gate of the second MOS transistor to the gate of the first MOS transistor, and a low-pass filter that is connected between the gate and the source of the second MOS transistor.

Abstract: According to one embodiment, a power supply circuit includes a smoothing capacitor that is charged with a charge current from an output transistor and outputs a voltage as an output voltage; a control loop that controls a conduction state of the output transistor depending on a difference value between the output voltage and a reference voltage; and a gain adjustment circuit that adjusts a gain of the control loop depending on magnitude of the charge current after the charge starts.

Abstract: According to an embodiment, a power source circuit includes a switching element that is connected between an input terminal and an output terminal, a driving circuit that supplies a PWM driving signal to the switching element, a first control path that integrates a differential voltage between an output voltage and a reference voltage to output a first control signal, a second control path that converts the differential voltage into a digital signal to output a second control signal, and a PWM signal generation circuit that generates a PWM signal dependent on the first and second control signals.

Abstract: According to an embodiment, a power source circuit includes a switching element that is connected between an input terminal and an output terminal, a driving circuit that supplies a PWM driving signal to the switching element, a first control path that integrates a differential voltage between an output voltage and a reference voltage to output a first control signal, a second control path that converts the differential voltage into a digital signal to output a second control signal, and a PWM signal generation circuit that generates a PWM signal dependent on the first and second control signals.

Abstract: An oscillation circuit includes a delay circuit that includes a first inverter having an input terminal connected to a first node, a delay adjustment circuit including first and second current supply paths through which the first node is charged in response to an output signal of the delay circuit. During charging of the first node, a current with positive temperature characteristics is supplied to the first node through the first current supply path, and a current with negative temperature characteristics is supplied to the first node through the second current supply path.

Abstract: According to one embodiment, a switched capacitor power supply circuit includes a switched capacitor power supply circuit unit that supplies a voltage obtained by converting an input voltage with a predetermined conversion ratio as an output voltage by switching a connection configuration between a plurality of capacitors that perform charge and discharge, and a control circuit that switches the connection configuration between the plurality of capacitors according to the output voltage to change the conversion ratio.