Abstract: A control circuit for a switching converter, where: the control circuit is configured to generate a switching control signal according to an output voltage of the switching converter to control a switching state of a power transistor in the switching converter, and to adjust an output current of the switching converter; and a change trend of a length of a switching period of the power transistor is opposite to a change trend of the output voltage.

Abstract: A power supply converter can include: an AC-DC linear circuit configured to rectify an AC input voltage to generate a DC voltage, and to transfer the input energy to an output terminal thereof during at least part of a time interval when the DC voltage is greater than an output voltage thereof, in order to generate a first output voltage and a first output current; and a conversion circuit configured to convert the first output voltage to a second output voltage, and to convert the first output current to a second output current for a load.

Abstract: A current drive circuit applied in an LED drive circuit that is compatible with a triac dimmer and is configured to generate a direct current bus voltage includes: a current generation circuit configured to receive the direct current bus voltage, and to generate a drive current based on a PWM dimming signal, in order to drive an LED load; and an input current regulation circuit configured to generate a regulation signal based on a duty cycle of the PWM dimming signal, in order to control an operation state of the triac dimmer.

Abstract: An apparatus for an LED driver with a silicon-controlled dimmer, can include: a bleeder circuit coupled to a DC bus of the LED driver; and a controller configured to control the bleeder circuit to draw a bleeder current from the DC bus when a conduction angel of the silicon-controlled dimmer is less than an angle threshold, in order to maintain a conduction state of the silicon-controlled dimmer.

Abstract: A voltage converter can include: an input end configured to receive an input voltage; an output end configured to generate an output voltage; N switched capacitor circuits sequentially coupled in series between the input end and the output end, where N is a positive integer greater than or equal to 2; where each switched capacitor circuit comprises a switch circuit and a flying capacitor, and at least the flying capacitor of an i-th switched capacitor circuit is configured as an output capacitor of an (i?1)-th switched capacitor circuit, where i is a positive integer that is greater than or equal to 2 and less than or equal to N; and a first energy storage element coupled to the output end.

Abstract: A power converter can include: a rectifier circuit; a silicon controlled dimmer coupled between an AC input terminal and an input terminal of the rectifier circuit; and a bleeder circuit coupled to an output terminal of the rectifier circuit, and being configured to provide a bleeder current after the silicon controlled dimmer is turned off. A method of controlling a power converter, can include: generating a bleeder current flowing though output terminals of a rectifier circuit of the power converter after a silicon controlled dimmer is turned off; and where the silicon controlled dimmer coupled to the rectifier circuit receives an AC input voltage.

Abstract: An apparatus for an LED driver with a silicon-controlled dimmer, can include: a bleeder circuit coupled to a DC bus of the LED driver; and a controller configured to control the bleeder circuit to draw a bleeder current from the DC bus when a conduction angle of the silicon-controlled dimmer is less than an angle threshold, in order to maintain a conduction state of the silicon-controlled dimmer.

Abstract: A detection circuit configured to detect the presence of a TRIAC dimmer for an LED driver, can include: a sampling circuit configured to receive a DC bus voltage, and to generate a voltage sampling signal that characterizes the DC bus voltage; and a detector configured to determine whether the LED driver is provided with the TRIAC dimmer in accordance with a duration of the voltage sampling signal being continuously greater than a first reference voltage.

Abstract: An apparatus can include: a linear drive circuit configured to control a drive current flowing through an LED load; a control circuit configured to acquire a conduction angle signal of a silicon-controlled rectifier dimmer and control the linear drive circuit; and the control circuit being configured to control the drive current to be decreased to reduce a current ripple and to maintain the silicon-controlled rectifier dimmer in a turn-on state when the conduction angle signal is less than a predetermined value.

Abstract: An apparatus can include: a light-emitting diode (LED) drive circuit having a silicon-controlled rectifier dimmer; and a bus voltage adjustment circuit configured to adjust a direct current bus voltage to delay a turn-on time instant of the silicon-controlled rectifier dimmer when a conduction angle signal is greater than an angle threshold.

Abstract: A control circuit for a switching converter, where: the control circuit is configured to generate a switching control signal according to an output voltage of the switching converter to control a switching state of a power transistor in the switching converter, and to adjust an output current of the switching converter; and a change trend of a length of a switching period of the power transistor is opposite to a change trend of the output voltage.

Abstract: A power converter can include: a rectifier circuit; a silicon controlled dimmer coupled between an AC input terminal and an input terminal of the rectifier circuit; and a bleeder circuit coupled to an output terminal of the rectifier circuit, and being configured to provide a bleeder current after the silicon controlled dimmer is turned off. A method of controlling a power converter, can include: generating a bleeder current flowing though output terminals of a rectifier circuit of the power converter after a silicon controlled dimmer is turned off; and where the silicon controlled dimmer coupled to the rectifier circuit receives an AC input voltage.

Abstract: A power converter can include: a rectifier circuit; a silicon controlled dimmer coupled between an AC input terminal and an input terminal of the rectifier circuit; and a bleeder circuit coupled to an output terminal of the rectifier circuit, and being configured to provide a bleeder current after the silicon controlled dimmer is turned off. A method of controlling a power converter, can include: generating a bleeder current flowing though output terminals of a rectifier circuit of the power converter after a silicon controlled dimmer is turned off; and where the silicon controlled dimmer coupled to the rectifier circuit receives an AC input voltage.

Abstract: The disclosure relates to a control circuit, a control method and a flyback converter of primary-side feedback control including the control circuit. When an input voltage is greater than a predetermined threshold, a peak value of an input current of the flyback converter is controlled to vary with the input voltage by the switching control signal. When the input voltage is less than the predetermined threshold, the peak value of the input current is controlled to be increased by the switching control signal to make demagnetization time of a secondary winding of the flyback converter be greater than a minimum time. Thus, the peak value of the primary-side current may not become too small because of a decreased input voltage, further avoiding occurrence of an error sampling after a blanking time due to excessive variations in demagnetization time.

Abstract: The disclosure relates to a flyback converter, a control circuit and a control method therefor. In the control method, a power stage circuit is controlled at a light load to operate alternatively in a pulse-width modulation mode (e.g., a constant switching frequency mode) and in a constant on time mode, in accordance with a voltage compensation signal. Thus, output energy may decrease rapidly and smoothly, without need for the control circuit to stop working. The flyback converter has increased efficiency at the light load and decreased output voltage ripple.

Abstract: A detection circuit configured to detect the presence of a TRIAC dimmer for an LED driver, can include: a sampling circuit configured to receive a DC bus voltage, and to generate a voltage sampling signal that characterizes the DC bus voltage; and a detector configured to determine whether the LED driver is provided with the TRIAC dimmer in accordance with a duration of the voltage sampling signal being continuously greater than a first reference voltage.

Abstract: An LED drive circuit with a SCR dimmer, a circuit module and a control method therefor are provided. In each cycle of the alternating current, the bleeding current during a time period for turning on the SCR dimmer is distinguished from the bleeding current in a time period from an instant at which the SCR dimmer is turned on to an instant at which the LED load is lit. The bleeder circuit is controlled to perform bleeding at the first current during the time period for turning on the SCR dimmer, and then perform bleeding at the second current which is less than the first current from the instant at which the SCR dimmer is turned on, so that an average bleeding current of the bleeder circuit in each cycle can be reduced, the bleed loss can be reduced, and the efficiency of the LED drive circuit can be improved.

Abstract: A detection circuit configured to detect the presence of a TRIAC dimmer for an LED driver, can include: a sampling circuit configured to receive a DC bus voltage, and to generate a voltage sampling signal that characterizes the DC bus voltage; and a detector configured to determine whether the LED driver is provided with the TRIAC dimmer in accordance with a duration of the voltage sampling signal being continuously greater than a first reference voltage.

Abstract: Driving an LED load using a driving circuit includes controlling a power transistor coupled in series with the LED load to operate in a linear mode when an input voltage varying periodically is higher than a driving voltage for the LED load; adjusting a transistor current flowing through the power transistor based on a difference between the input voltage and the driving voltage, without calculating an error between an average current flowing through the LED load and a desired current; and where the transistor current is controlled to be decreased when the difference between the input voltage and the driving voltage is relatively large, in order to reduce a conduction loss of the power transistor, and to cause the average current flowing through the LED load to meet a predetermined requirement of driving the LED load.