Abstract: A first switch and a second switch connected in series to both terminals of a DC power source. A signal generation circuit generates a feedback signal based on the DC voltage detected by the voltage detection circuit, and outputs the feedback signal, the feedback signal for turning the first and second switches on and off. A burst oscillation circuit that generates a burst oscillation signal based on a feedback signal and turns the first switch element and the second switch element on and off based on the burst oscillation signal when the standby state is detected. The burst oscillation circuit comprises a capacitor and a rapid charge circuit. When this device returns from standby state to normal state, the rapid charging circuit charges the capacitor after the feedback signal exceeds the cancellation threshold voltage.

Abstract: A burst oscillation circuit operates switches in a burst oscillation mode based on a feedback signal. A first burst operation cancellation threshold voltage comparator compares a first burst operation cancellation threshold voltage set higher than a voltage of the feedback signal that a load current reaches the standby threshold and a voltage of the feedback signal, and outputs a first output signal. A second burst operation cancellation threshold voltage comparator compares a second burst operation cancellation threshold voltage set lower than the voltage of the feedback signal that the load current reaches the standby threshold and higher than a voltage of the feedback signal during a non-oscillation period of the burst oscillation operation and the voltage of the feedback signal and outputs a second output signal. A standby cancellation circuit generates a standby cancel signal to cancel the standby state based on the first and second output signal.

Abstract: A burst oscillation circuit operates switches in a burst oscillation mode based on a feedback signal. A first burst operation cancellation threshold voltage comparator compares a first burst operation cancellation threshold voltage set higher than a voltage of the feedback signal that a load current reaches the standby threshold and a voltage of the feedback signal, and outputs a first output signal. A second burst operation cancellation threshold voltage comparator compares a second burst operation cancellation threshold voltage set lower than the voltage of the feedback signal that the load current reaches the standby threshold and higher than a voltage of the feedback signal during a non-oscillation period of the burst oscillation operation and the voltage of the feedback signal and outputs a second output signal. A standby cancellation circuit generates a standby cancel signal to cancel the standby state based on the first and second output signal.

Abstract: A first switch and a second switch connected in series to both terminals of a DC power source. A signal generation circuit generates a feedback signal based on the DC voltage detected by the voltage detection circuit, and outputs the feedback signal, the feedback signal for turning the first and second switches on and off. A burst oscillation circuit that generates a burst oscillation signal based on a feedback signal and turns the first switch element and the second switch element on and off based on the burst oscillation signal when the standby state is detected. The burst oscillation circuit comprises a capacitor and a rapid charge circuit. When this device returns from standby state to normal state, the rapid charging circuit charges the capacitor after the feedback signal exceeds the cancellation threshold voltage.

Abstract: Disclosed is a switching control circuit for performing an ON-OFF control of a switching element. The switching control circuit includes a first external terminal; a second external terminal; a passive element connected between the first external terminal and the second external terminal; and a function setting circuit, which performs a function setting based on a constant of the passive element. An electric potential at the first external terminal and an electric potential at the second external terminal are controlled.

Abstract: A disclosed switching control circuit is a switching control circuit for performing an ON-OFF control of a switching element. The switching control circuit includes a first external terminal, a electric potential on which is controlled; a second external terminal, a electric potential on which is controlled; a passive element, which is connected between the first external terminal and the second external terminal; and a function setting circuit, which performs a function setting based on a constant of the passive element.

Abstract: First and second switch are connected in series to both terminals of a DC power source. A series circuit comprising a reactor, a primary winding of a transformer, and a capacitor connected in series, and is connected to a node between the first and second switches and one terminal of the DC power source. A rectifier smoothing circuit rectifies and smoothens a voltage generated across a secondary winding of the transformer and outputs a DC voltage. A control circuit alternately turns the first and second switches on and off. A voltage detection circuit detects the DC voltage from the rectifier smoothing circuit. A signal generation circuit generates a feedback signal from the DC voltage detected by the voltage detection circuit, and outputs the signal for turning the first and second switches on and off. A load current detection circuit detects load current contained in resonance current flowing through the capacitor.

Abstract: First and second switch are connected in series to both terminals of a DC power source. A series circuit comprising a reactor, a primary winding of a transformer, and a capacitor connected in series, and is connected to a node between the first and second switches and one terminal of the DC power source. A rectifier smoothing circuit rectifies and smoothens a voltage generated across a secondary winding of the transformer and outputs a DC voltage. A control circuit alternately turns the first and second switches on and off. A voltage detection circuit detects the DC voltage from the rectifier smoothing circuit. A signal generation circuit generates a feedback signal from the DC voltage detected by the voltage detection circuit, and outputs the signal for turning the first and second switches on and off. A load current detection circuit detects load current contained in resonance current flowing through the capacitor.

Abstract: A switching power-supply device comprises: a transformer; a switching element connected in series with a primary coil; an output voltage generation circuit to generate an output voltage from a voltage generated in a secondary coil; a control circuit power-supply-voltage generation circuit to generate a power-supply voltage from a voltage generated in an auxiliary coil; a feedback control circuit to control an ON width of the switching element by using the voltage generated in the auxiliary coil; a voltage reduction detection circuit to output a pulse signal to the secondary coil when a reduction of the output voltage is detected; a voltage-reduction-signal detection circuit to detect the voltage reduction signal transmitted to the primary coil from the secondary coil; and a trigger circuit to output a trigger signal to turn on the switching element when the voltage reduction signal is detected by the voltage-reduction-signal detection circuit.

Abstract: A switching power supply apparatus includes a transformer having a primary winding, a secondary winding, and an auxiliary winding, a switching element coupled in series to the primary winding; an output circuit section generating a voltage output from power transferred from the primary winding to the secondary winding in response to a switching operation of the switching element, a feedback signal generation circuit section configured to, during a secondary side conduction period in which an electric current flows through the secondary winding, generate a feedback signal having a signal level corrected based on a length of the secondary side conduction period, from an auxiliary winding voltage induced in the auxiliary winding, and a control circuit section driving the switching element based on the feedback signal.

Abstract: A switching power supply is provided to supply an AC input voltage. The supply includes a control circuit configured to detect a voltage of the AC power source in a voltage waveform, and switch elements in a synchronous rectification switching mode in synchronization with polarities of the voltage waveform when the AC input voltage is equal to or greater than a predetermined voltage value. The control unit also operates the switching without synchronization with the polarities when the AC input voltage is smaller than the predetermined voltage value.

Abstract: A switching power supply apparatus includes a transformer having a primary winding, a secondary winding, and an auxiliary winding, a switching element coupled in series to the primary winding; an output circuit section generating a voltage output from power transferred from the primary winding to the secondary winding in response to a switching operation of the switching element, a feedback signal generation circuit section configured to, during a secondary side conduction period in which an electric current flows through the secondary winding, generate a feedback signal having a signal level corrected based on a length of the secondary side conduction period, from an auxiliary winding voltage induced in the auxiliary winding, and a control circuit section driving the switching element based on the feedback signal.

Abstract: A switching power supply is provided to supply an AC input voltage. The supply includes a control circuit configured to detect a voltage of the AC power source in a voltage waveform, and switch elements in a synchronous rectification switching mode in synchronization with polarities of the voltage waveform when the AC input voltage is equal to or greater than a predetermined voltage value. The control unit also operates the switching without synchronization with the polarities when the AC input voltage is smaller than the predetermined voltage value.

Abstract: A switching power-supply device comprises: a transformer; a switching element connected in series with a primary coil; an output voltage generation circuit to generate an output voltage from a voltage generated in a secondary coil; a control circuit power-supply-voltage generation circuit to generate a power-supply voltage from a voltage generated in an auxiliary coil; a feedback control circuit to control an ON width of the switching element by using the voltage generated in the auxiliary coil; a voltage reduction detection circuit to output a pulse signal to the secondary coil when a reduction of the output voltage is detected; a voltage-reduction-signal detection circuit to detect the voltage reduction signal transmitted to the primary coil from the secondary coil; and a trigger circuit to output a trigger signal to turn on the switching element when the voltage reduction signal is detected by the voltage-reduction-signal detection circuit.

Abstract: A switching power supply is provided to supply an AC input voltage. The supply includes a control circuit configured to detect a voltage of the AC power source in a voltage waveform, and switch elements in a synchronous rectification switching mode in synchronization with polarities of the voltage waveform when the AC input voltage is equal to or greater than a predetermined voltage value. The control unit also operates the switching without synchronization with the polarities when the AC input voltage is smaller than the predetermined voltage value.