Abstract: According to embodiments, a semiconductor device includes a first switching element in which a first reference voltage is input to a gate; a second switching element in which a first voltage is input to a gate; a third switching element to which the first switching element is in Darlington connection; a fourth switching element to which the second switching element is in Darlington connection; a first current mirror circuit to regulate currents flowing in the third and fourth switching elements; a fifth switching element switched between ON and OFF states based on a difference between the first reference and the first voltages; a constant current circuit; a second current mirror circuit; and a voltage setting resistance element between a source of the first switching element and a gate of the third switching element or between a source of the second switching element and a gate of the fourth switching element.

Abstract: According to embodiments, a semiconductor device includes a first switching element in which a first reference voltage is input to a gate; a second switching element in which a first voltage is input to a gate; a third switching element to which the first switching element is in Darlington connection; a fourth switching element to which the second switching element is in Darlington connection; a first current mirror circuit to regulate currents flowing in the third and fourth switching elements; a fifth switching element switched between ON and OFF states based on a difference between the first reference and the first voltages; a constant current circuit; a second current mirror circuit; and a voltage setting resistance element between a source of the first switching element and a gate of the third switching element or between a source of the second switching element and a gate of the fourth switching element.

Abstract: According to one embodiment, a level shift circuit includes first through fourth transistors, a control circuit, and first and second generating circuits. The control circuit outputs a first voltage obtained by level-shifting an input voltage to a first terminal. The first transistor supplies a first electric current to the control circuit for outputting the first voltage to the first terminal. The second transistor increases the first electric current. The first generating circuit generates a first pulse signal for controlling the second transistor. The third transistor supplies a second electric current to the first terminal for generating a second voltage corresponding to a first supply of a low-potential side. The fourth transistor increases the second electric current. The second generating circuit generates a second pulse signal for controlling the fourth transistor.

Abstract: According to one embodiment, a power supply circuit includes a load switch, a switching control unit, a first control unit, and a second control unit. The load switch is connected to a power supply and switches between an ON state connecting the power supply to a load and an OFF state disconnecting the power supply from the load. The switching control unit outputs a first signal for controlling switching of the load switch between the ON and OFF states. The first control unit increases an output voltage of the load switch in a steady manner over a predetermined period of time when the load switch is switched to the ON state in response to the first signal. The second control unit causes a charging current to flow to the load switch after the first signal is output from the switching control unit.

Abstract: According to one embodiment, a level shift circuit includes first through fourth transistors, a control circuit, and first and second generating circuits. The control circuit outputs a first voltage obtained by level-shifting an input voltage to a first terminal. The first transistor supplies a first electric current to the control circuit for outputting the first voltage to the first terminal. The second transistor increases the first electric current. The first generating circuit generates a first pulse signal for controlling the second transistor. The third transistor supplies a second electric current to the first terminal for generating a second voltage corresponding to a first supply of a low-potential side. The fourth transistor increases the second electric current. The second generating circuit generates a second pulse signal for controlling the fourth transistor.

Abstract: A power supply circuit includes a charge pump circuit configured to generate an output voltage by boosting an input voltage received at an input terminal and to provide the output voltage at an output terminal. A current supply circuit of the power supply circuit includes a first current source that supplies a first current that increases with time. The current supply circuit supplies current to the input terminal of the charge pump circuit. An insulated gate field effect transistor has a control electrode connected to the output terminal of the charge pump circuit. The insulated gate field effect transistor has a first electrode receiving a first voltage and a second electrode outputting a second voltage to, for example, a load circuit. The level of the second voltage can be determined according to the levels of the output voltage of the charge pump circuit and the first voltage.

Abstract: According to one embodiment, a power supply circuit includes a load switch, a switching control unit, a first control unit, and a second control unit. The load switch is connected to a power supply and switches between an ON state connecting the power supply to a load and an OFF state disconnecting the power supply from the load. The switching control unit outputs a first signal for controlling switching of the load switch between the ON and OFF states. The first control unit increases an output voltage of the load switch in a steady manner over a predetermined period of time when the load switch is switched to the ON state in response to the first signal. The second control unit causes a charging current to flow to the load switch after the first signal is output from the switching control unit.

Abstract: A power source circuit includes a first transistor as an output switch, a second transistor as a load switch, a reference voltage generating section, a soft start voltage generating section, a feedback voltage generating section, first and second error amplifiers, and first and second offset control sections. The first error amplifier controls a conduction state of the first transistor based on a difference between a soft start voltage obtained by adding an offset voltage to a soft start voltage or a reference voltage, whichever is smaller, and a feedback voltage. The second error amplifier controls a conduction state of the second transistor based on a difference between a soft start voltage obtained by adding an offset voltage to the soft start voltage and the feedback voltage.

Abstract: An input circuit connected to a semiconductor circuit is configured to receive a voltage indicating an on/off operation state of a power supply and to output a voltage that is lower than a breakdown voltage of the semiconductor circuit. The input circuit includes a first nMOS transistor and a resistor element. The first nMOS transistor has a drain receiving an outside voltage, a gate receiving a bias voltage higher than a power supply voltage inputted to a semiconductor circuit, and a source connected to the semiconductor circuit. The first nMOS transistor has a breakdown voltage higher than the power supply voltage inputted to the semiconductor circuit. One end of the resistor element connects with the source of the first nMOS transistor, while the other end connects with a reference potential of the semiconductor circuit.

Abstract: According to one embodiment, a voltage regulator includes an output transistor, a voltage detector, a controller, and a discharge circuit. The output transistor is connected between a power supply terminal and an output terminal. The voltage detector is connected between the output terminal and a ground terminal. The voltage detector is configured to divide an output voltage between the output terminal and the ground terminal according to an inputted voltage switching signal and generates a first voltage on the ground terminal side and a second voltage having a polarity the same as a polarity of the first voltage and having an absolute value lower than or equal to an absolute value of the first voltage. The controller is configured to detect a difference between the first voltage and a reference voltage and control the output transistor.

Abstract: A DC-DC converter includes an input terminal connected to one end of a boot capacitor and a boot terminal connected to the other end of the boot capacitor. A first transistor has a drain connected to the input terminal and a source connected to a switch terminal. A second transistor has a drain connected to the switch terminal and a source connected to ground. Agate of the first transistor is connected to a first driver circuit, which is connected to the boot capacitor. A gate of the second transistor is connected to a second driver circuit. The DC-DC converter includes an oscillator circuit outputting a pulse signal and a voltage detecting circuit which detects the voltage of the boot capacitor. The voltage detecting circuit outputs a signal based on the detected voltage. A timing circuit controls the first and second drivers in accordance with the detected voltage signal.

Abstract: According to one embodiment, a switching circuit includes a high-side switch, a rectifier, and a driver. The high-side switch is connected between a high potential terminal and an output terminal. The rectifier is connected between the output terminal and a low potential terminal, forward direction of the rectifier is a direction from the low potential terminal to the output terminal. The driver is connected between the high potential terminal and the output terminal. The driver switches a high-side switch ON based on a high-side control signal. The driver switches the high-side switch OFF when a first short detector detects shorts of the output terminal with the low potential terminal after a first period longer than a backward recovery time of the rectifier until the high-side control signal changing.

Abstract: The short-circuit protection circuit includes a first logic circuit that outputs the first logic signal so as to turn off the fourth MOS transistor in a case where the first gate voltage signal has a value that turns on the first MOS transistor and the switching terminal has a terminal voltage between a predetermined first threshold value and the second potential. The short-circuit protection circuit includes a first detecting circuit that compares a first detected voltage between the second end of the first resistor and the first end of the third MOS transistor with a predetermined first reference voltage and outputs, in a case where the first detected voltage is closer to the second potential than the first reference voltage, a first detection signal indicating that the switching terminal and the second potential are short-circuited.

Abstract: According to one embodiment, a switching circuit includes a high-side switch, a rectifier, and a driver. The high-side switch is connected between a high potential terminal and an output terminal. The rectifier is connected between the output terminal and a low potential terminal, and forward direction of the rectifier is the direction from the low potential terminal to the output terminal. The driver supplies a first voltage to a control terminal of the high-side switch in accordance with a high-side control signal and turns the high-side switch on. The driver supplies a second voltage being higher than the first voltage to the control terminal of the high-side switch when the voltage of the output terminal increases to not less than a predetermined value.

Abstract: According to one embodiment, a switching circuit includes a high-side switch, a rectifier, and a driver. The high-side switch is connected between a high potential terminal and an output terminal. The rectifier is connected between the output terminal and a low potential terminal, forward direction of the rectifier is a direction from the low potential terminal to the output terminal. The driver is connected between the high potential terminal and the output terminal. The driver switches a high-side switch ON based on a high-side control signal. The driver switches the high-side switch OFF when a first short detector detects shorts of the output terminal with the low potential terminal after a first period longer than a backward recovery time of the rectifier until the high-side control signal changing.

Abstract: According to one embodiment, a level shifter includes a current generator, a current switch, and a protection circuit. The current generator is connected between a first high potential terminal and a first low potential terminal and configured to generate a first current at a first output line. The current switch is connected between a second high potential terminal and a second low potential terminal. The current switch is configured to receive the first current with a higher current supply capacity than the current generator and pass the first current or cut off the first current in accordance with an input signal. The protection circuit is connected to the first output line between the current generator and the current switch. The protection circuit is configured to limit an electric potential of the first output line.

Abstract: According to one embodiment, a voltage regulator includes an output transistor, a voltage detector, a controller, and a discharge circuit. The output transistor is connected between a power supply terminal and an output terminal. The voltage detector is connected between the output terminal and a ground terminal. The voltage detector is configured to divide an output voltage between the output terminal and the ground terminal according to an inputted voltage switching signal and generates a first voltage on the ground terminal side and a second voltage having a polarity the same as a polarity of the first voltage and having an absolute value lower than or equal to an absolute value of the first voltage. The controller is configured to detect a difference between the first voltage and a reference voltage and control the output transistor.