Abstract: A control method of a switching circuit, a control circuit of the switching circuit, and the switching circuit are provided. The switching circuit includes an inductor or a transformer. An operational amplification is performed on an output feedback voltage and a first reference voltage of the switching circuit to obtain a compensation voltage. The compensation voltage controls an on-time of a main switch of the switching circuit. When the current of the inductor or the transformer drops to a threshold, after a time, the main switch is switched from off to on, and the output feedback voltage controls the time. When the output feedback voltage is higher than a first threshold voltage, the compensation voltage is pulled down. When the output feedback voltage is lower than a second threshold voltage, the compensation voltage is pulled up.

Abstract: The present disclosure provides a power transistor driving method. When a power transistor is turned off, a drain-source voltage of the power transistor is detected, and when the power transistor is an N-type component, and a change rate of the drain-source voltage of the power transistor along with time is lower than a first slope threshold, the power transistor is pulled down in a first current; when the change rate of the drain-source voltage of the power transistor along with the time is higher than the first slope threshold, a driving pole of the power transistor is pulled down in a second current; and when the change rate of the drain-source voltage of the power transistor along with the time is lower than the first slope threshold again, a pull-down switch is turned on or the driving pole of the power transistor is pulled down in a third current.

Abstract: The present disclosure provides an LED driving circuit and an LED driving method, which may be applied to a switching power supply driving circuit and a linear driving circuit. The LED driving circuit includes an adjusting tube and a driving control circuit of the adjusting tube. The adjusting tube receives an input voltage, and the driving control circuit adjusts the adjusting tube to output an output current to be expected. A reference generating circuit samples an output voltage of the LED driving circuit to obtain an output voltage sampling signal and a reference current signal corresponding to the output voltage sampling signal. A current adjusting circuit samples the output current to obtain an output current sampling signal, receives the corresponding reference current signal, and controls a conduction state of the adjusting tube according to the output current sampling signal and the reference current signal.

Abstract: A control method of a single live line charging circuit, a control circuit of a single live line charging circuit, and a single live line charging circuit are provided. The single live line charging circuit includes a first switch, a first conduction element, a first inductor, a second switch, a second conduction element, a third switch, a first input end and a second input end; the first input end is connected to a first end of the first switch through the second conduction element; the first switch, the first conduction element and the first inductor constitute a buck circuit; the first input end is connected to a reference ground through the second switch, the second input end is connected to the reference ground through the third switch, and an alternating current input is connected to the first input end through a load circuit.

Abstract: The present disclosure provides a power transistor driving method, a driving circuit and a switching circuit. When the power transistor is an N-type component, a driving pole of the power transistor is pulled down in a first current, and when a time period recorded by the timer reaches a first time period, a pull-down switch is turned on or the driving pole of the power transistor is pulled down in a second current; the driving pole of the power transistor is pulled down by the pull-down switch; when a timer is started from a moment at which the power transistor is turned off, the first time period is higher than a time period from a moment at which a switching tube is turned off to a moment at which the change rate of the drain-source voltage of the power transistor along with the time is higher than the first slope.

Abstract: A control method and a control circuit for a switching power supply circuit and the switching power supply circuit. The switching power supply circuit includes a main switching transistor, a synchronous rectifier and an inductive element. When a switching signal indicates that the synchronous rectifier is turned from on to off, and the main switching transistor is turned from off to on, a gate voltage of the synchronous rectifier is pulled down to be lower than a threshold voltage of the synchronous rectifier and higher than a zero voltage by using a resistor-capacitor delay effect and timing is started. When a gate voltage of the main switching transistor is detected to rise to a first voltage or the timing reaches a first time, the gate voltage of the synchronous rectifier is pulled down to the zero voltage.

Abstract: A clamping switch abnormality detection method, a clamping switch abnormality detection circuit and a switch circuit are provided, wherein an active clamping flyback circuit includes a clamping switch, a main switch and a transformer. When a clamping switch control signal is active, a switching node voltage or a voltage on an auxiliary winding or an magnetizing inductor current is detected, and when the switching node voltage or the voltage on the auxiliary winding or the magnetizing inductor current oscillates, or the switching node voltage is less than a first voltage threshold or the voltage on the auxiliary winding is less than a second voltage threshold, the clamping switch is abnormal or a clamping switch driving circuit is abnormal. The switching node is a common node of the transformer and the main switch, and the transformer includes a primary winding, a secondary winding and the auxiliary winding.

Abstract: An active clamping flyback circuit and a control method are disclosed, comprising a flyback circuit, a clamping circuit and a clamping control circuit. The active clamping flyback circuit comprises a transformer, a main transistor, and a freewheeling diode or a synchronous rectifier, an output feedback circuit is coupling to an auxiliary winding of the transformer and outputs a feedback voltage through a divided voltage The clamping circuit comprises a first capacitor and a first transistor coupling in series, In a discontinuous conduction mode, the clamping control circuit starts timing from a turn-off time of the first transistor, and ends timing until the feedback voltage is reduced to zero voltage, to obtain a first time, The clamping control circuit adjusts a turn-off moment of next switching cycle of the first transistor so that the first time of the next switching cycle is close to a first threshold.

Abstract: A control method of a switching circuit, a control circuit of the switching circuit, and the switching circuit are provided. The switching circuit includes an inductor or a transformer. An operational amplification is performed on an output feedback voltage and a first reference voltage of the switching circuit to obtain a compensation voltage. The compensation voltage controls an on-time of a main switch of the switching circuit. When the current of the inductor or the transformer drops to a threshold, after a time, the main switch is switched from off to on, and the output feedback voltage controls the time. When the output feedback voltage is higher than a first threshold voltage, the compensation voltage is pulled down. When the output feedback voltage is lower than a second threshold voltage, the compensation voltage is pulled up.

Abstract: A clamping switch abnormality detection method, a clamping switch abnormality detection circuit and a switch circuit are provided, wherein an active clamping flyback circuit includes a clamping switch, a main switch and a transformer. When a clamping switch control signal is active, a switching node voltage or a voltage on an auxiliary winding or an magnetizing inductor current is detected, and when the switching node voltage or the voltage on the auxiliary winding or the magnetizing inductor current oscillates, or the switching node voltage is less than a first voltage threshold or the voltage on the auxiliary winding is less than a second voltage threshold, the clamping switch is abnormal or a clamping switch driving circuit is abnormal. The switching node is a common node of the transformer and the main switch, and the transformer includes a primary winding, a secondary winding and the auxiliary winding.

Abstract: The present disclosure provides a power transistor driving method. When a power transistor is turned off, a drain-source voltage of the power transistor is detected, and when the power transistor is an N-type component, and a change rate of the drain-source voltage of the power transistor along with time is lower than a first slope threshold, the power transistor is pulled down in a first current; when the change rate of the drain-source voltage of the power transistor along with the time is higher than the first slope threshold, a driving pole of the power transistor is pulled down in a second current; and when the change rate of the drain-source voltage of the power transistor along with the time is lower than the first slope threshold again, a pull-down switch is turned on or the driving pole of the power transistor is pulled down in a third current.

Abstract: The present disclosure provides a power transistor driving method, a driving circuit and a switching circuit. When the power transistor is an N-type component, a driving pole of the power transistor is pulled down in a first current, and when a time period recorded by the timer reaches a first time period, a pull-down switch is turned on or the driving pole of the power transistor is pulled down in a second current; the driving pole of the power transistor is pulled down by the pull-down switch; when a timer is started from a moment at which the power transistor is turned off, the first time period is higher than a time period from a moment at which a switching tube is turned off to a moment at which the change rate of the drain-source voltage of the power transistor along with the time is higher than the first slope.

Abstract: The present disclosure provides an LED driving circuit and an LED driving method, which may be applied to a switching power supply driving circuit and a linear driving circuit. The LED driving circuit includes an adjusting tube and a driving control circuit of the adjusting tube. The adjusting tube receives an input voltage, and the driving control circuit adjusts the adjusting tube to output an output current to be expected. A reference generating circuit samples an output voltage of the LED driving circuit to obtain an output voltage sampling signal and a reference current signal corresponding to the output voltage sampling signal. A current adjusting circuit samples the output current to obtain an output current sampling signal, receives the corresponding reference current signal, and controls a conduction state of the adjusting tube according to the output current sampling signal and the reference current signal.

Abstract: This invention provides a switching power supply controlling circuit, the switching power supply comprises an upper transistor and a lower transistor, the switching power supply controlling circuit comprises a boost circuit, an input terminal of the boost circuit is connected to an input terminal of the switching power supply, the boost circuit output a first voltage to control a working state of the boost circuit, driving the upper transistor to be in an on state. The switching power supply controlling circuit adopts a boost circuit to provide a driving power for the upper transistor, and there is no need to set a bootstrap pin or a bootstrap capacitor.

Abstract: A control method and a control circuit for a switching power supply circuit and the switching power supply circuit. The switching power supply circuit includes a main switching transistor, a synchronous rectifier and an inductive element. When a switching signal indicates that the synchronous rectifier is turned from on to off, and the main switching transistor is turned from off to on, a gate voltage of the synchronous rectifier is pulled down to be lower than a threshold voltage of the synchronous rectifier and higher than a zero voltage by using a resistor-capacitor delay effect and timing is started. When a gate voltage of the main switching transistor is detected to rise to a first voltage or the timing reaches a first time, the gate voltage of the synchronous rectifier is pulled down to the zero voltage.

Abstract: This invention provides a switching power supply controlling circuit, the switching power supply comprises an upper transistor and a lower transistor, the switching power supply controlling circuit comprises a boost circuit, an input terminal of the boost circuit is connected to an input terminal of the switching power supply, the boost circuit output a first voltage to control a working state of the boost circuit, driving the upper transistor to be in an on state. The switching power supply controlling circuit adopts a boost circuit to provide a driving power for the upper transistor, and there is no need to set a bootstrap pin or a bootstrap capacitor.

Abstract: An active clamping flyback circuit is disclosed, comprising a flyback circuit, a clamping circuit and a clamping control circuit, wherein the flyback circuit comprises a transformer, a main transistor, and a freewheeling diode or a synchronous rectifier, an output feedback circuit is coupling to an auxiliary winding of the transformer and outputs a feedback voltage through a divided voltage; the clamping circuit comprises a first capacitor and a first transistor coupling in series, one end of the first capacitor is coupling to a high voltage end, one end of the first transistor is coupling to a common end of the main transistor and a primary winding of the transformer; the clamping control circuit adjusts a turn-off time of next switching cycle of the first transistor so that the first time of the next switching cycle is close to a first threshold.

Abstract: A power device driving method and a driving circuit for a switching circuit having a main switching transistor, a synchronous rectifier, and an inductive element. When a switching signal indicates that the synchronous rectifier is turned from on to off and the main switching transistor is turned from off to on, a gate voltage of the synchronous rectifier is pulled down to be lower than a threshold voltage of the synchronous rectifier and higher than zero voltage by a body effect of a MOS transistor, and timing is started. When detecting that a gate voltage of the main switching transistor rises to a first voltage or the timing reaches a first time, the gate voltage of the synchronous rectifier is pulled down to the zero voltage.

Abstract: Disclosed a drive method, a drive circuit for a power switch and a power supply system. During the turning-on period of the power switch, which can be roughly divided into three processes, a current limiting module is used to limit the current flowing through the power switch for preventing current overshoot, a logic control module is used for controlling the current limiting module not to operate before the turning-on period and the control terminal of the power switch is turned off; during the turning-on period, a feedback circuit adjusts the gate voltage of the power switch for controlling the current flowing through the power switch to reach a predetermined limited value quickly and then maintain at the limited value until the power switch is fully turned on. The current limiting module can be employed in various embodiments.

Abstract: A supply method of a dual-chip power circuit, and a dual-chip power circuit are provided. The dual-chip power circuit includes an inductor, a conduction element, a first chip and a second chip. The first chip includes a control circuit and a supply circuit. The second chip includes a first switch and a drive control circuit, and the drive control circuit is connected to a control end of the first switch. The supply method includes the following steps. When starting, the drive control circuit controls the power circuit to operate in an open-loop state; and if the output voltage of the supply circuit is detected to be established, the supply circuit supplies power to the control circuit, the drive control circuit of the second chip receives an output voltage of the first chip, and then the power circuit operates in a closed-loop state.