Abstract: A current detection circuit includes: at least one current detector configured to detect a current flowing through a second switch element of at least one switching output stage configured to connect a first switch element and the second switch element in series; an analog signal generator configured to generate an analog signal corresponding to the current detected by the at least one current detector; a converter configured to receive the analog signal, convert the analog signal to a digital signal corresponding to an integrated value of the analog signal, and output the digital signal; and a corrector configured to correct any one of a drive voltage, an input, and an output of the converter according to an on-DUTY of the second switch element.

Abstract: In a normal state in which a main power supply supplies an input voltage having a first level, a step-down converter is enabled. In this state, the step-down converter steps down the input voltage and supplies a power supply voltage having a second level to a load. In the normal state, a step-up converter is operated in a forward direction. In this state, the step-up converter steps up the power supply voltage so as to charge a backup capacitor using a voltage having a third level. In a power supply disconnection state in which a disconnection of the input voltage occurs, the step-up converter is operated in a reverse direction. In this state, the step-up converter steps down a capacitor voltage across the backup capacitor, and supplies the power supply voltage having the second voltage level to the load.

Abstract: A power supply adapter receives an AC voltage, converts the AC voltage into a DC voltage, and supplies the DC voltage to an electronic device. A DC/DC converter converts the voltage smoothed by a smoothing capacitor into the DC voltage. A device-side connector is connected to the DC/DC converter via a cable, and is configured to be detachably connected to the electronic device. The device-side connector includes a detection unit detecting whether or not the electronic device is connected, and generates a connection detection signal indicating whether or not the electronic device is connected. A control circuit of the DC/DC converter is connected to the detection unit of the device-side connector via the cable, and is set to an operating state when the connection detection signal indicates that the electronic device is connected, and is set to a non-operating state when the connection detection signal indicates that the electronic device is not connected.

Abstract: A DC/DC converter comprises: inductors L provided for respective channels; switching circuits provided for the respective channels; and a controller configured to change the number of channels to be activated, i.e., K, according to an amount of a load current IOUT that flows through a load, and to control the switching circuits that correspond to the activated channels such that a feedback voltage VFB that corresponds to an output voltage VOUT matches a predetermined target voltage VREF. The controller activates only a single channel in a lightest load state. The inductance L of the inductor L provided for the aforementioned single channel is set to a value that differs from the inductances of the inductors L of the other channels so as to provide high efficiency in the lightest load state.

Abstract: A charging circuit receives electric power from a solar battery, and charges a secondary battery. A charging current detection unit generates a detection signal that corresponds to a charging current supplied from a DC/DC converter to the secondary battery. A control circuit generates a reference voltage that corresponds to the detection signal. A driving unit generates a pulse signal having a duty ratio that is adjusted such that the voltage output from the solar battery matches the reference voltage, and performs switching of a switching transistor according to the pulse signal. A control circuit adjusts the reference voltage such that the reference voltage becomes greater.

Abstract: A power supply adapter receives an AC voltage, converts the AC voltage into a DC voltage, and supplies the DC voltage to an electronic device. A DC/DC converter converts the voltage smoothed by a smoothing capacitor into the DC voltage. A device-side connector is connected to the DC/DC converter via a cable, and is configured to be detachably connected to the electronic device. The device-side connector includes a detection unit detecting whether or not the electronic device is connected, and generates a connection detection signal indicating whether or not the electronic device is connected. A control circuit of the DC/DC converter is connected to the detection unit of the device-side connector via the cable, and is set to an operating state when the connection detection signal indicates that the electronic device is connected, and is set to a non-operating state when the connection detection signal indicates that the electronic device is not connected.

Abstract: A charging circuit receives electric power from a solar battery, and charges a secondary battery. A charging current detection unit generates a detection signal that corresponds to a charging current supplied from a DC/DC converter to the secondary battery. A control circuit generates a reference voltage that corresponds to the detection signal. A driving unit generates a pulse signal having a duty ratio that is adjusted such that the voltage output from the solar battery matches the reference voltage, and performs switching of a switching transistor according to the pulse signal. A control circuit adjusts the reference voltage such that the reference voltage becomes greater.

Abstract: the output amplifiers requiring a bias voltage can be activated or deactivated individually, and a bias acceleration circuit for rapidly increasing the magnitude of a bias voltage in time can be provided in or with the bias circuit, whereby even in case of the capacitance of the capacitor included in the bias circuit being increased for improving the power supply rejection ratio (PSRR), the rise in the bias voltage can be increased so that the pop sound which arises when the bias circuit is activated can be still diminished.

Abstract: In a converter which operates in a serial-parallel manner and performs analog-to-digital (A/D) conversion, the number of high bits is made more than half the entire number of bits, with the number of low bits is given by half the entire number of bits, thereby acquiring high-bit and low-bit data. When no match exists between the high-bit data and the low-bit data, the high-bit data can be modified by means of the low-bit data.

Abstract: In a converter which operates in a serial-parallel manner and performs analog-to-digital (A/D) conversion, the number of high bits is made more than half the entire number of bits, with the number of low bits is given by half the entire number of bits, thereby acquiring high-bit and low-bit data. When no match exists between the high-bit data and the low-bit data, the high-bit data can be modified by means of the low-bit data.

Abstract: the output amplifiers requiring a bias voltage can be activated or deactivated individually, and a bias acceleration circuit for rapidly increasing the magnitude of a bias voltage in time can be provided in or with the bias circuit, whereby even in case of the capacitance of the capacitor included in the bias circuit being increased for improving the power supply rejection ratio (PSRR), the rise in the bias voltage can be increased so that the pop sound which arises when the bias circuit is activated can be still diminished.