Abstract: According to one embodiment, a chopper stabilized amplifier includes an input unit, a first chopper, a first amplifier, and a switch circuit. The input unit receives a differential input signal at a first input terminal and a second input terminal. The first chopper modulates the differential input signal based on a first control signal and an inverse signal of the first control signal. The first amplifier amplifies the signals with the modulated differential output from the first chopper. The switch circuit is provided between the input unit and the first chopper, and receives a second control signal and reduces input currents which flow in the first chopper when the first chopper performs a modulating operation, by using an operation with the second control signal.

Abstract: According to one embodiment, an operational amplifier includes first and second input terminals, an output terminal, differential circuitry, and output circuitry. The differential circuitry including first and second nodes, and first and second transistors. The output circuitry including third through fifth nodes, and third through eighth transistors. The third transistor being coupled to the first node at a gate and coupled to the third node at one end. The fourth transistor being coupled to the second node at a gate and coupled to the fourth node at one end. The fifth transistor being coupled to the fourth node at a gate and coupled to the third node at one end. The sixth transistor being coupled to the fourth node at each of a gate and one end.

Abstract: According to one embodiment, a semiconductor device includes an output circuit; a detection circuit; and a control circuit. The output circuit includes a first transistor which includes one end of a current path connected to an output node, receives a first input signal, and outputs a first voltage, and a second transistor which includes one end of a current path connected to the output node, receives a second input signal, and outputs a second voltage. The output circuit outputs the first voltage or the second voltage. The detection circuit detects the voltage and outputs a detection result. The control circuit controls back-gate potentials of the first and the second transistors.

Abstract: According to one embodiment, a semiconductor device includes an output circuit; a detection circuit; and a control circuit. The output circuit includes a first transistor which includes one end of a current path connected to an output node, receives a first input signal, and outputs a first voltage, and a second transistor which includes one end of a current path connected to the output node, receives a second input signal, and outputs a second voltage. The output circuit outputs the first voltage or the second voltage. The detection circuit detects the voltage and outputs a detection result. The control circuit controls back-gate potentials of the first and the second transistors.

Abstract: According to one embodiment, a gate control circuit includes a controller, a delay circuit, a power circuit, a boosting circuit, a first transistor, and a control circuit. The controller outputs first and second control signals based on a control signal from outside. The delay circuit delays the first control signal. The power circuit is capable of controlling a power supply voltage to be output based on the delayed first control signal. The boosting circuit is capable of boosting and outputting an input voltage. The first transistor has one end connected to an output node of the boosting circuit, and the other end grounded. The control circuit is capable of controlling a gate voltage of the first transistor based on the second control signal.

Abstract: According to one embodiment, a gate control circuit includes a controller, a delay circuit, a power circuit, a boosting circuit, a first transistor, and a control circuit. The controller outputs first and second control signals based on a control signal from outside. The delay circuit delays the first control signal. The power circuit is capable of controlling a power supply voltage to be output based on the delayed first control signal. The boosting circuit is capable of boosting and outputting an input voltage. The first transistor has one end connected to an output node of the boosting circuit, and the other end grounded. The control circuit is capable of controlling a gate voltage of the first transistor based on the second control signal.

Abstract: In an embodiment, an output voltage control circuit includes a detection circuit that is connected to an input voltage terminal and configured to detect a voltage level of an input voltage received at the input voltage terminal and output one or more detection signals corresponding to a comparison of the voltage level of the input voltage to a plurality of predetermined voltage ranges. A selection circuit is connected to the detection circuit and configured to select a first voltage from among a plurality of first voltages according the one or more detection signals from the detection circuit. An output circuit is connected to the selection circuit and configured to output a second voltage by boosting the input voltage based on the first voltage selected by the selection unit.

Abstract: In an embodiment, an output voltage control circuit includes a detection circuit that is connected to an input voltage terminal and configured to detect a voltage level of an input voltage received at the input voltage terminal and output one or more detection signals corresponding to a comparison of the voltage level of the input voltage to a plurality of predetermined voltage ranges. A selection circuit is connected to the detection circuit and configured to select a first voltage from among a plurality of first voltages according the one or more detection signals from the detection circuit. An output circuit is connected to the selection circuit and configured to output a second voltage by boosting the input voltage based on the first voltage selected by the selection unit.

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: According to one embodiment, a constant voltage power circuit includes a bias generator, a reference voltage generator, and a constant voltage generator, a bias switch, a constant voltage controller. The bias generator generates a first bias voltage. The reference voltage generator is connected to the bias generator and generates a reference voltage. The constant voltage generator generates a constant voltage. The bias switch switches a bias supplied to the constant voltage generator in accordance with a switch control signal controlling the bias switch. The constant voltage controller obtains a detected voltage corresponding to the constant voltage or a power supply voltage, and generates a constant voltage control signal and the switch control signal. The constant voltage control signal sets an operating state of the constant voltage generator to an enable state or a disable state.

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 light-emitting element driving circuit comprises a current supplier serially connected to a light-emitting element and operative to supply a current to the light-emitting element; and a switching unit operative to control switching between the states of the current supplied to the light-emitting element from the current supplier. The switching unit includes a current path consisting of a diode and a semiconductor switching element. The diode is connected in parallel with the light-emitting element and in a forward direction directed from an anode to a cathode of the light-emitting element. The semiconductor switching element is connected serially to the diode and operative to switch between the states of conductive and non-conductive based on a control signal. A voltage drop across the current path when the semiconductor switching element is made conductive is determined lower than a forward voltage of the light-emitting element when it emits light.

Abstract: A light-emitting element driving circuit comprises a current supplier serially connected to a light-emitting element and operative to supply a current to the light-emitting element; and a switching unit operative to control switching between the states of the current supplied to the light-emitting element from the current supplier. The switching unit includes a current path consisting of a diode and a semiconductor switching element. The diode is connected in parallel with the light-emitting element and in a forward direction directed from an anode to a cathode of the light-emitting element. The semiconductor switching element is connected serially to the diode and operative to switch between the states of conductive and non-conductive based on a control signal. A voltage drop across the current path when the semiconductor switching element is made conductive is determined lower than a forward voltage of the light-emitting element when it emits light.