Abstract: A switching power supply apparatus includes a PFM control circuit that outputs a clock signal Set such that a switching frequency of a switching element varies in accordance with a load state. The clock signal Set determines a turn-on timing of the switching element. A reference value of a current flowing through the switching element determines a turn-off timing of the switching element. A modulation signal is applied to the turn-off timing of the switching element to modulate one of a peak value of a drain current flowing through the switching element and an on-time of the switching element. Input control is performed separately on the clock signal Set and the modulation signal. Accordingly, even when the clock signal Set and the modulation signal contribute to each other to offset each other, modulation effects are not cancelled.

Abstract: A switching power supply device of the present disclosure includes a device connection state detection circuit that detects a connection state in a load device connection terminal, in a power supply system having the load device connection terminal. The device connection state detection circuit includes a transformer, a switching element, a pulse generator, and a waveform detection circuit. The waveform detection circuit detects a voltage or a current generated at a connecting point between a primary winding wire of the transformer and the switching element in response to operation of a pulse signal. The waveform detection circuit compares the voltage or the current with a predetermined reference value, and outputs an output signal in response to a comparison result to an OFF terminal.

Abstract: A switching power supply apparatus of the present disclosure is a device connection state detection circuit that detects a connection state in a load device connection terminal in a power supply system having the load device connection terminal. The device connection state detection circuit includes a transformer, a switching element, a pulse generator, and a waveform detection circuit. The waveform detection circuit detects a voltage or a current generated in a primary winding wire or a secondary winding wire of the transformer in accordance with operation of a pulse signal, compares the detected voltage or current with a preset reference value, and outputs an output signal in accordance with a comparison result, to an OFF terminal.

Abstract: Provided is a switching power supply apparatus that shifts to an OFF mode when electronic equipment is on standby, and includes: an OFF mode delay circuit that delays shifting to the OFF mode; and an electric storage unit and a power supply circuit that function as a power supply source of an OFF mode control circuit. With the configuration, the power consumption can almost be eliminated, and the switching power supply apparatus can start without any charge in an electricity storage component such as a primary battery or a secondary battery.

Abstract: A direct current power supply circuit includes an alternating-current power supply; a rectification circuit for generating a direct-current voltage from an alternating-current voltage; a charging switch having an input terminal connected to the rectification circuit, the charging switch outputting an output voltage according to an input value input to a control terminal; a capacitor and a control circuit, which are connected to an output terminal; and a charging switch control circuit for generating a switch-on signal when the output voltage is equal to or lower than a first reference voltage value, and for generating a switch-off signal when the output voltage is equal to or higher than a second reference voltage value higher than the first reference voltage value, wherein a charging period setting circuit including at least one of the rectification circuit and the charging switch control circuit sets a charging period in which a charging current flows into the capacitor and a non-charging period in which th

Abstract: A converter includes: a bridge diode; an X capacitor provided upstream of the bridge diode; a smoothing capacitor provided downstream of the bridge diode; an AC shutoff detection circuit which outputs an AC shutoff detection signal when input AC voltage is shut off; and a discharging circuit which is connected to a connection point at which the cathode of the bridge diode and the smoothing capacitor are connected, and allows residual charges in the smoothing capacitor and the X capacitor to be discharged when the AC shutoff detection signal is output, and the discharging circuit includes a JFET which has a drain terminal connected to the above connection point and lowers discharge voltage; and a first discharging switch element connected to the source terminal of the JFET.

Abstract: A switching power supply apparatus of the present disclosure is a device connection state detection circuit that detects a connection state in a load device connection terminal in a power supply system having the load device connection terminal. The device connection state detection circuit includes a transformer, a switching element, a pulse generator, and a waveform detection circuit. The waveform detection circuit detects a voltage or a current generated in a primary winding wire or a secondary winding wire of the transformer in accordance with operation of a pulse signal, compares the detected voltage or current with a preset reference value, and outputs an output signal in accordance with a comparison result, to an OFF terminal.

Abstract: A control circuit varies an intermittent oscillation frequency using a period signal. A period signal period signal frequency is set to a frequency lower than the intermittent oscillation frequency, or is set to be higher than the intermittent oscillation frequency and to a frequency other than integer multiples of the intermittent oscillation frequency. The phase difference of the period signal with respect to an intermittent oscillation control signal is set so that the distribution of the intermittent oscillation frequency is dispersed.

Abstract: Provided is a switching power supply apparatus that shifts to an OFF mode when electronic equipment is on standby, and includes: an OFF mode delay circuit that delays shifting to the OFF mode; and an electric storage unit and a power supply circuit that function as a power supply source of an OFF mode control circuit. With the configuration, the power consumption can almost be eliminated, and the switching power supply apparatus can start without any charge in an electricity storage component such as a primary battery or a secondary battery.

Abstract: A switching power supply apparatus includes a PFM control circuit that outputs a clock signal Set such that a switching frequency of a switching element varies in accordance with a load state. The clock signal Set determines a turn-on timing of the switching element. A reference value of a current flowing through the switching element determines a turn-off timing of the switching element. A modulation signal is applied to the turn-off timing of the switching element to modulate one of a peak value of a drain current flowing through the switching element and an on-time of the switching element. Input control is performed separately on the clock signal Set and the modulation signal. Accordingly, even when the clock signal Set and the modulation signal contribute to each other to offset each other, modulation effects are not cancelled.

Abstract: A control circuit varies an intermittent oscillation frequency using a period signal. A period signal period signal frequency is set to a frequency lower than the intermittent oscillation frequency, or is set to be higher than the intermittent oscillation frequency and to a frequency other than integer multiples of the intermittent oscillation frequency. The phase difference of the period signal with respect to an intermittent oscillation control signal is set so that the distribution of the intermittent oscillation frequency is dispersed.

Abstract: A converter includes: a bridge diode; an X capacitor provided upstream of the bridge diode; a smoothing capacitor provided downstream of the bridge diode; an AC shutoff detection circuit which outputs an AC shutoff detection signal when input AC voltage is shut off; and a discharging circuit which is connected to a connection point at which the cathode of the bridge diode and the smoothing capacitor are connected, and allows residual charges in the smoothing capacitor and the X capacitor to be discharged when the AC shutoff detection signal is output, and the discharging circuit includes a JFET which has a drain terminal connected to the above connection point and lowers discharge voltage; and a first discharging switch element connected to the source terminal of the JFET.

Abstract: A switching power supply apparatus includes: a turn-on control circuit which generates a turn-on signal; a feedback control circuit which generates a reference voltage VEAO indicating a limitation level for a current ID flowing into a switching element, by referring to a feedback signal IFB indicating an output current voltage VOUT, the limitation level which decreases as the output direct current voltage becomes greater; an overcurrent protection level setting circuit which generates a reference voltage VLR indicating an overcurrent protection level; a current detecting terminal; an offset current generating circuit which provides an offset current IIS from the current detecting terminal, the offset current IIS which is greater as the output current voltage VOUT is greater; and a turn-off control circuit which generates a turn-off signal by comparing a voltage applied to the current detecting terminal with each of the reference voltage VEAO, and the reference voltage VLR.

Abstract: The present invention includes a voltage clamping circuit 6 for outputting a voltage signal, which has been clamped to a predetermined voltage, from the drain voltage of a switching element 1, and a turn-on detection circuit 7 for detecting the turn-on timing of the switching element 1 from the voltage signal. Thus it is possible to turn on the switching element 1 at the minimum value of the drain voltage without adding external terminals.

Abstract: A driving circuit includes a generator configured to generate a driving signal having plural levels of voltage at which a power switching device is turned on. The driving circuit also includes a switching controller configured to switch between the plural levels of voltage at which the power switching device is turned on. The driving circuit further includes a load current detector configured to output a load current detection signal to the switching controller, the load current detection signal indicating whether or not a current flowing through the power switching device exceeds a threshold, wherein the switching controller is configured to perform the switching based on the load current detection.

Abstract: In a high-voltage semiconductor switching element, in addition to a first emitter region that is necessary for switching operations, a second emitter region, which is electrically connected with the first emitter region through a detection resistor in current detection means and is electrically connected with the current detection means, is formed. No emitter electrode is formed on the second emitter region, while an emitter electrode is formed on a part of a base region that is adjacent to the second emitter region.

Abstract: A driving circuit includes a generation unit configured to generate a driving signal for turning on and off a power switching device, the driving signal having plural levels of voltage at which the power switching device is turned on. The driving circuit also includes a switching control unit configured to switch between the plural levels of voltage at which the power switching device is turned on, depending on a status of the power switching device.

Abstract: In a high-voltage semiconductor switching element, in addition to a first emitter region that is necessary for switching operations, a second emitter region, which is electrically connected with the first emitter region through a detection resistor in current detection means and is electrically connected with the current detection means, is formed. No emitter electrode is formed on the second emitter region, while an emitter electrode is formed on a part of a base region that is adjacent to the second emitter region.

Abstract: A switching power supply apparatus includes: a turn-on control circuit which generates a turn-on signal; a feedback control circuit which generates a reference voltage VEAO indicating a limitation level for a current ID flowing into a switching element, by referring to a feedback signal IFB indicating an output current voltage VOUT, the limitation level which decreases as the output direct current voltage becomes greater; an overcurrent protection level setting circuit which generates a reference voltage VLR indicating an overcurrent protection level; a current detecting terminal; an offset current generating circuit which provides an offset current IIS from the current detecting terminal, the offset current IIS which is greater as the output current voltage VOUT is greater; and a turn-off control circuit which generates a turn-off signal by comparing a voltage applied to the current detecting terminal with each of the reference voltage VEAO, and the reference voltage VLR.

Abstract: A borate-based crystal excellent in uniformity and reliability, which is useful as an optical wavelength conversion device, etc., and can be easily produced at low cost in a short period of time, by the steps of dissolving water-soluble starting materials in water to prepare an aqueous solution, evaporating water in the aqueous solution followed by sintering or evaporating the water and not sintering, thereby forming a crystal growth material, and melting the resultant material to grow a crystal. Further, a highly reliable laser oscillation apparatus can be achieved by using this crystal as an optical wavelength conversion device.